Problem:
Score : 100 points

Problem Statement

You are given two integers A and B as the input. Output the value of A + B.

However, if A + B is 10 or greater, output error instead.

Constraints

A and B are integers.

1 ≤ A, B ≤ 9

Input

Input is given from Standard Input in the following format:

A B

Output

If A + B is 10 or greater, print the string error (case-sensitive); otherwise, print the value of A + B.

Sample Input 1

6 3

Sample Output 1

9

Sample Input 2

6 4

Sample Output 2

error

Solution in C++ (GCC 9.2.1) (judge verdict: Wrong Answer)

#include<bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;
using ll = long long;
using p = pair<int,int>;
const long long INF = 1ll << 60;


int main() {
  int N; cin >> N;
  int s[N];
  rep(i,N){
    cin >> s[i];
  }
  ll ans = 0;
  rep(bit,(1<<N)){
    ll sum = 0;
    rep(i,N){
      if  (bit & (1<<i)){
        sum += s[i];
      }
    }
    if (sum%10 == 0) sum = 0;
    ans = max(ans,sum);
  }
  cout << ans << endl;
	return 0;
}