public class Triangle {

public static void main(String[] args) {

            int y = 1;

                for(int i=1; i<= 4 ;i++){

                        for(int j=1; j <= i ; j++){
                                System.out.print(y + " ");
                                y = y + 1;
                        }

                        System.out.println("");
                }
        }
}