Help me in solving RCPITCP29 problem

help
1

My issue

i can’t solve it

My code

#include <stdio.h>

int main() 

{
    int a,b;
    a=23;
    b=20;
    
    printf("enter value of a:%d");
    scanf("%d", & a);
    
    printf("enter value of b: ");
    scanf("%d", & b);
    
   
	 
	 return 0;
}

Learning course: Learn C Programming
Problem Link: https://www.codechef.com/learn/course/rcpit-programming-c/RCPITLPC05/problems/RCPITCP29