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 << k - n << endl;       else {         if ((n & 1) == (k & 1))           cout << 0 << endl;         else           cout << 1 << endl;       }     }     return 0;   }   