func_code_string: #include <bits/stdc++.h>   using namespace std;   using ll = long long;   const ll inf = 1e18;   const int N = 2 * 1e5 + 10;   ll res;   ll a[N];   void solve() {     ll n, k;     cin >> n >> k;     if (n == 1) {       cout << 0 <<   n ;       return;     }     if (n == 2) {       cout << k <<   n ;       return;     }     cout << 2 * k <<   n ;   }   int main(int argc, char const *argv[]) {     ios_base::sync_with_stdio(0);     cin.tie(NULL);     cout.tie(NULL);     ll t = 1;     cin >> t;     while (t--) {       solve();     }   }   