func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       int n, k;       cin >> n >> k;       if (n == k)         cout <<  0  << endl;       else if (k > n)         cout << k - n << endl;       else {         if ((n - k) % 2 == 0)           cout <<  0  << endl;         else           cout <<  1  << endl;       }     }   }   