Subtrack without subtrack operator

#include<stdio.h>
int main(){
        int a,b;
    int sum;
    printf("Enter any two integers: ");
scanf("%d%d",&a,&b);
    sum = a + ~b + 1;
    printf("Difference of two integers: %d",sum);
    return 0;
}

Output:
Enter any two integers:4  2
Difference of two integers:2