/*
 * Author: nskybytskyi
 * Time:   2022-01-13 15:08:45
 */

#include <bits/stdc++.h>
using namespace std;

int main() {
  cin.tie(0)->sync_with_stdio(0);

  int n, m;
  cin >> n >> m;

  vector<int64_t> a(n);
  for (auto& ai : a) {
    cin >> ai;
  }

  auto can = [&] (int mi) -> bool {
    int64_t balance = 0;
    for (auto ai : a) {
      ai += balance;
      if (ai < mi) {
        return false;
      } else {
        balance = ai - mi;
      }
    }
    return true;
  };

  int lo = 0, hi = *max_element(a.begin(), a.end()) + 1;
  while (hi - lo > 1) {
    int mi = (lo + hi) >> 1;
    if (can(mi)) {
      lo = mi;
    } else {
      hi = mi;
    }
  }
  cout << lo << "\n";

  return 0;
}