#include<stdio.h>
main( )
{
    int choice, num1, num2 ;
    while ( 1 )
    {
        printf ( "\n1. add two numbers" ) ;
        printf ( "\n2. subtract two number" ) ;
        printf ( "\n3. multiply two numbers" ) ;
        printf ( "\n4. Exit" ) ;
        printf ( "\nYour choice? " ) ;
        scanf ( "%d", &choice ) ;
        switch ( choice )
        {
            case 1 :
            /* logic for add two numbers */
            printf("Enter two numbers :\t");
            scanf("%d %d", &num1, &num2);
            printf("Sum = %d\n", num1+num2);
            break ;
            case 2 :
            /* logic for subtract two numbers */
            printf("Enter two numbers :\t");
            scanf("%d %d", &num1, &num2);
            printf("Sum = %d\n", num1-num2);
            break ;
            case 3 :
            /* logic for multiply two numbers */
            printf("Enter two numbers :\t");
            scanf("%d %d", &num1, &num2);
            printf("Sum = %d\n", num1*num2);
            break ; 
            case 4 :
            exit(0) ;
            default;
              printf("enter correct choice\n");
        }
    }
}