#include<bits/stdc++.h>
using namespace std;
int n,m,a[1000005],maxx=-1;
bool check(int x)
{
    int sum=0;
    for(int i=1;i<=n;i++)
        a[i]>x?sum+=a[i]-x:sum+=0;
    return (sum>=m?1:0);
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&a[i]);
        maxx=max(a[i],maxx);
    }
    int l=0,r=maxx,ans,mid;
    while(l<=r)
    {
        mid=l+r>>1;
        check(mid)?ans=mid,l=mid+1:r=mid-1;
    }
    printf("%d",ans);
}