// created : 2026/02/01 15:06:19 #pragma GCC optimize("Ofast") #pragma GCC optimize("O3") #include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> using namespace std; using namespace __gnu_pbds; #define int long long #define pb push_back #define all(v) v.begin(), v.end() void solve() { int n; cin >> n; vector<int> vt; for (int i = 0; i < n; i++) { int x; cin >> x; vt.pb(x); } int best = LLONG_MAX; for (int i = 0; i < min(n, 1000ll); i++) { int x = 0; vector<int> vt2 = vt; while (true) { vector<int> vt3; bool ok2 = false; for (int j = 1; j < i; j++) { if (vt2[j - 1] >= vt2[j]) { vt3.pb(j); vt2[j]++; ok2 = true; } } for(int j = i; j < n - 1; j++) { if(vt2[j] <= vt2[j + 1]) { vt3.pb(j); vt2[j]++; ok2 = true; } } if(!ok2) { break; } for(int j = 0; j < vt3.size() - 1; j++) { if(vt3[j] + 1 == vt3[j + 1]) { while(j + 1 < vt3.size() and vt3[j] + 1 == vt3[j + 1]) { j++; } x++; } else { x++; } } if(vt3.size() == 1) { x++; } } for(int i = 0; i < n - 1; i++) { if(vt2[i] == vt2[i + 1]) { vt2[i]++; x++; } } best = min(best, x); } cout << best << '\n'; } signed main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); int t = 1; // cin >> t; while (t--) { solve(); } }