//CF1603B Moderate Modular Mode
#include <bits/stdc++.h>
#define int long long
using namespace std;
int t, a, b;
signed main() {
	cin >> t;
	while(t--) {
		int a, b;
		cin >> a >> b;
		if(a > b) cout << a + b << '\n';
		else cout << b - b % a / 2 << '\n';
	}
}

这个代码本地没过，交到CF上去就过了，什么情况?