Unknown Error

#include <bits/stdc++.h>
using namespace std;
int n;
inline fun(int x){
	int ans=0,t=x;
	while(t!=0)
		ans=ans*10+t%10,t/=10;
	return ans;
}
main() {
	scanf("%d",&n);
	while(n--){
		int a,b;
		scanf("%d%d",&a,&b);
		int c=fun(fun(a)+fun(b));
		printf("%d\n",c);
	}
	return 0;
}

Help大佬!