func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve() {     long long a, b;     cin >> a >> b;     if (a == b) {       cout << a << endl;       return;     } else if (a > b) {       cout << a + b << endl;       return;     } else {       if (b % a == 0) {         cout << b << endl;         return;       } else {         long long x = b - a - b % a;         if (x == 0) {           cout << a + (b - a) / 2;         } else {           cout << (b + x) / 2;         }         cout << endl;         return;       }     }     cout << -1 << endl;   }   signed main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     int t = 1;     cin >> t;     while (t--) {       solve();     }     return 0;   }   