#include <bits/stdc++.h>
using namespace std;
#include <atcoder/modint>
using namespace atcoder;
using mint = modint998244353;
//using mint = modint1000000007;
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using tlll = tuple<ll, ll, ll>;
constexpr ll INF = 1LL << 60;
template<class T> bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
ll safemod(ll A, ll M) {return (A % M + M) % M;}
ll divfloor(ll A, ll B) {if (B < 0) {return divfloor(-A, -B);} return (A - safemod(A, B)) / B;}
ll divceil(ll A, ll B) {if (B < 0) {return divceil(-A, -B);} return divfloor(A + B - 1, B);}
#define FINALANS(A) do {cout << (A) << '\n'; exit(0);} while (false)

ll N, M;
vector<ll> A;

bool isok(ll x)
{
  vector<ll> B(N);
  for (ll i = 0; i < N; i++)
  {
    B.at(i) = A.at(i);
  }

  ll tmp = 0;
  for (ll i = 0; i < N; i++)
  {
    tmp += B.at(i) - x;
    if (tmp < 0)
      return false;
  }
  return true;
}

int main()
{
  cin >> N >> M;
  A.resize(N);
  for (ll i = 0; i < N; i++)
  {
    cin >> A.at(i);
  }

  ll ok = 0, ng = INF;
  while (abs(ok - ng) > 1)
  {
    ll mid = (ok + ng) / 2;
    if (isok(mid))
      ok = mid;
    else
      ng = mid;
  }
  ll ans = ok / M;
  cout << ans << endl;
}