func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       long long ma = -1e15, need = 0;       for (int i = 0; i < n; i++) {         long long a;         cin >> a;         ma = max(a, ma);         need = max(need, ma - a);       }       long long ans = 0;       while ((1ll << ans) - 1 < need) ans++;       cout << ans << endl;     }   }   