hdu 1229 还是A+B

#include<iostream>#include<cmath>using namespace std;int main(){int a, b, k;while(scanf("%d%d%d", &a, &b, &k) != EOF && (a||b)){if(a % (int)pow(10.0, k) == b % (int)pow(10.0, k))printf("-1\n");elseprintf("%d\n", a+b);}return 0;}