program to calculate roman numbers .....i.e roman number calculator

import java.util.*; import java.io.*; class romancalci { public static void main(String args[])throws IOException { int decimal1 = 0;int decimal2=0; Scanner input=new Scanner(System.in); System.out.print("Enter a Roman Number 1st: "); String roman1 = input.next(); System.out.println("Enter a Roman Number 2nd: "); String roman2=input.next(); String romanNumeral1 = roman1.toUpperCase(); String romanNumeral2=roman2.toUpperCase(); int x = 0;int result=0;int largest=0;int number=0; int l1=romanNumeral1.length(); int l2=romanNumeral2.length(); String numeral1=romanNumeral1; String numeral2=romanNumeral2;
String s="IC"; String s3="IVC";

 String newNumeral = numeral1.replace("XL", "XXXX"); // Replaces XL with XXXX

 String newNumeral2 = newNumeral.replace("XC", "LXXXX"); // Replaces XC with LXXXX

 String newNumeral3 = newNumeral2.replace("CD", "CCCC"); // Replaces CD with CCCC

 String newNumeral4 = newNumeral3.replace("CM", "DCCCC"); // Replaces CM with DCCC

 String newNumeral5 = newNumeral4.replace("IV", "IIII"); // Replaces IV with IIII

 String newNumeral6 = newNumeral5.replace("IX", "VIIII"); 

l1=newNumeral6.length();

String newNumeralz = numeral2.replace("XL", "XXXX"); // Replaces XL with XXXX

 String newNumeralz2 = newNumeralz.replace("XC", "LXXXX"); // Replaces XC with LXXXX

 String newNumeralz3 = newNumeralz2.replace("CD", "CCCC"); // Replaces CD with CCCC

 String newNumeralz4 = newNumeralz3.replace("CM", "DCCCC"); // Replaces CM with DCCC

 String newNumeralz5 = newNumeralz4.replace("IV", "IIII"); // Replaces IV with IIII

 String newNumeralz6 = newNumeralz5.replace("IX", "VIIII");  
      l2=newNumeralz6.length();

if(newNumeral6.equals(s)) { System.out.println("enter the correct roman value 1 in place of IC"); newNumeral6="0"; }

do { char convert1 = newNumeral6.charAt(x); switch (convert1) { case 'M': decimal1 += 1000; break;

                    case 'D':
                            decimal1 += 500;
                            break;

                    case 'C':
                            decimal1 += 100;
                            break;

                    case 'L':
                            decimal1 += 50;
                            break;

                    case 'X':
                            decimal1 += 10;
                            break;

                    case 'V':
                            decimal1 += 5;
                            break;

                    case 'I':
                            decimal1 += 1;
                            break;
                    }
                    x++;
            } while (x < l1);
            System.out.println("Decimal Number1 is: " + decimal1);
             x=0;
             if(newNumeralz6.equals("ic"))

{ System.out.println("enter the correct roman value 2 in place of IC"); newNumeralz6="0"; }

do { char convert2 = newNumeralz6.charAt(x); switch (convert2) { case 'M': decimal2 += 1000; break;

                    case 'D':
                            decimal2 += 500;
                            break;

                    case 'C':
                            decimal2 += 100;
                            break;

                    case 'L':
                            decimal2 += 50;
                            break;

                    case 'X':
                            decimal2 += 10;
                            break;

                    case 'V':
                            decimal2 += 5;
                            break;

                    case 'I':
                            decimal2 += 1;
                            break;
                    }
                    x++;

            } while (x < l2);
            System.out.println("Decimal Number2 is: " + decimal2);


          System.out.println("enter the choice for calculating \n 1 for addition  \n 2 for subtraction \n 3 for multiplication");
          int choice=input.nextInt();
          switch(choice)

{ case 1: result=decimal1+decimal2; System.out.println("the calculated result in integer is= "+ result); break; case 2: result=decimal1-decimal2; System.out.println("the calculated result in integer is= "+ result); break; case 3: result=decimal1*decimal2; System.out.println("the calculated result in integer is= "+ result); break; default: System.out.println("enter the correct choice"); }

      number=result;
      String roman="";



    while(number>=1000){
        roman += "M";
        number-=1000;
    }

    while(number>=900){
        roman += "CM";
        number-=900;
    }

    while(number>=500){
        roman += "D";
        number-=500;
    }

    while(number>=400){
        roman += "CD";
        number-=400;
    }

    while(number>=100){
        roman += "C";
        number-=100;
    }

    while(number>=90){
        roman += "XC";
        number-=90;
    }

    while(number>=50){
        roman += "L";
        number-=50;
    }

    while(number>=40){
        roman += "XL";
        number-=40;
    }

    while(number>=10){
        roman += "X";
        number-=10;
    }

    while(number>=9){
        roman += "IX";
        number-=9;
    }

    while(number>=5){
        roman += "V";
        number-=5;
    }

    while(number>=4){
        roman += "IV";
        number-=4;
    }

    while(number>=1){
        roman += "I";
        number-=1;
    }

    System.out.println("the final result in roman ="+ roman);
}

}