#include<stdio.h>
int main(){
    int m1,m2;
    if (scanf("%d %d",&m1, &m2) != 2)
    {
    printf("Invalid input");
    return 0;
    }
    if (m1 < 0 || m2 < 0){
        printf("Invalid input");
    }else{
        int total = m1 + m2;
        print("%d",total);
    }
    return 0;
}