func_code_string: #include <bits/stdc++.h>   const int N = 1e6 + 10;   const int mod = 1e9 + 7;   const int inf = 0x3f3f3f3f;   const double eps = 1e-8;   const double pi = acos(-1);   using namespace std;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int t;     cin >> t;     while (t--) {       int n, k;       cin >> n >> k;       int ans;       if (n < k)         ans = k - n;       else {         if (n % 2 == k % 2)           ans = 0;         else           ans = 1;       }       cout << ans << endl;     }     return 0;   }   