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: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>

#define _CRT_SECURE_NO_WARNINGS
#define TLong long long 

// fact(n)
int fact(int n){
	if(n == 1)	return 1;
	else return (n * fact(n - 1));
}

// combination(n,r)
int combination(int n, int r){

	if(r == 0 || r == n)	return 1;
	else if(r == 1)	return n;
	return (combination(n - 1, r - 1) + combination(n - 1, r));
}

// gcd(a,b)
int gcd(int a,int b){
	int ret;
	ret = (b == 0) ? a : gcd(b, a % b);
	return ret;
}

// lcm(a.b)
int lcm(int a,int b){
	return (a * b) / gcd(a,b);
}

// qsort(array, size, sizeof(int),comp);
int comp(const int *a,const int *b){
	return (*a - *b);
}

// append(array,*size,addNum)
void append(int *array,int *size,int num){
	realloc(array, sizeof(int) * (*size + 1));
	array[(*size)] = num;
	++(*size);
}

// pop(array,*size) & nongetpop(array,*size)
int pop(int *array,int *size){
	int temp = array[(*size - 1)];
	realloc(array,sizeof(int) * (*size - 1));
	--(*size);
	return temp;
}

void nongetpop(int *array,int *size){
	realloc(array,sizeof(int) * (*size - 1));
	--(*size);
}

int main(int argc, char const *argv[]){
	int a,b;
	scanf("%d%d",&a,&b);
	if(a + b < 10)	printf("%d\n", a + b);
	else printf("error\n");
	return 0;
}