class Solution {

public:

    int inf = ~0u >> 1;

    int reverse(int x) {

        if(x == 0)return 0;

        long long tx = x;

        long long ans = 0;

        for(int i = 0;tx;i++){

            ans = ans * 10 + tx % 10;

            tx /= 10;

        }

        return int(ans) == ans?ans:0;

    }

};