#include<bits/stdc++.h> using namespace std; const int kMaxN=1e5+4; unsigned long long n,k,a[kMaxN],minn=LLONG_MAX; bool C(unsigned long long x){ unsigned long long s=0,w=0; for(int i=1;i<=n;i++){ if(a[i]+s<x){ w+=(x-a[i]-s+i-1)/i; s+=(x-a[i]-s+i-1)/i*i; } } return w<=k; } int main(){ cin>>n>>k; for(int i=1;i<=n;i++){ cin>>a[i]; minn=min(minn,a[i]); } unsigned long long l=0,r=minn+k*n; while(l<r){ unsigned long long mid=(l+r+1)/2; if(C(mid)){ l=mid; }else{ r=mid-1; } } cout<<l; return 0; }