func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve() {     int n;     cin >> n;     vector<int> a(n);     for (int i = 0; i < int(n); i++) cin >> a[i];     long long diff = 0;     int m = a[0];     int ans = 0;     for (int i = 0; i < n; i++) {       if (a[i] >= m) {         m = a[i];       } else {         diff = (m - a[i]);         int d = floor(log2(diff)) + 1;         ans = max(d, ans);       }     }     cout << ans << endl;   }   int main() {     cin.tie(0);     ios_base::sync_with_stdio(false);     int t = 1;     cin >> t;     while (t--) {       solve();     }     return 0;   }   