#include <stdio.h>

int main() {
    int a, b;
    scanf("%d %d", &a, &b);
    
    if (a < 0 || b < 0){
        printf("Warning: Expenses should be non-negative");
    }else{
        printf("%d",a + b);
    }else{
        printf("Invalid Input")
    }   
    return 0;
}