#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<n;i++)
#define int long long
int n,m;
int a[200010];

bool f(int x){
  int amari=0;
  rep(i,n){
    if(a[i]+amari>=x*m){
      amari=(a[i]+amari-x*m);
      continue;
    }
    else return false;
  }
  return true;
}

signed main(){
  cin>>n>>m;
  rep(i,n) cin>>a[i];
  int ac=0;int wa=1001001001;
  while(wa-ac>1){
    int wj=(ac+wa)/2;
    if(f(wj)) ac=wj;
    else wa=wj;   
  }
  cout<<ac<<endl;

  return 0;
}