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 5.4.1) (judge verdict: Runtime Error)

#include <stdio.h>

int main()
{
	int a[27] = { 0 };
	int i, ans = 0;
	char s[27] = { 0 };

	scanf("%s", s);

	for (i = 0; s[i] != '\n'; i++){
		++a[s[i] - 'a'];
	}
	for (i = 0; i < 27; i++){
		if (a[i] >= 2)
		{
			ans++;
		}
	}
	if (ans >= 1)
		printf("no");
	else
		printf("yes");

	return 0;
}