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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    ll s, tot = 0;
    cin >> n >> s;
    vector<int> a(n);
    for(auto &&v : a) cin >> v, tot += v;
    sort(a.rbegin(), a.rend());
    if(a[0] >= s){
        cout << a[0] << '\n';
        return 0;
    }
    s--;
    cout << (tot + s - 1) / s << '\n';
}