#include <bits/stdc++.h>
using namespace std;
int a[1000005];
int n,m;
int l = 0,r = 0;
int ans = 0;
bool lumbering(int h){
    int num = 0;
    for(int i = 1;i <= n;i++){
        if(a[i] > h) num += a[i] - h;
    }
    return num;
}
int main(){
    scanf("%d%d",&n,&m);
    for(int i = 1;i <= n;i++){
        scanf("%d",&a[i]);
        if(a[i] > r) r =a[i];
    }
    while(l <= r){
        int mid = (l + r) / 2;
        if(lumbering(mid) >= m){
            ans = mid;
            r = mid - 1;
        }
        else{
            l = mid + 1;
        }
    }
    printf("%d",ans);
    return 0;
}