#include<bits/stdc++.h>
#define ll long long
#define N 200001
using namespace std;
int t,n,k,a[N],num,ans;
int main(){
	freopen("ntarsis_set.in","r",stdin);
	freopen("ntarsis_set.out","w",stdout);
	//cin>>t;
	t=1;
	while(t--){
		cin>>n>>k;
		for(int i=1;i<=n;i++) cin>>a[i];
		if(a[1]>1){
			cout<<1<<endl;
			continue;
		}
		ans=1;
		num=0;
		while(k--){
			ans+=num;
			while(num<n&&a[num+1]<=ans){
				num++;
				ans++;
			}
		}
		cout<<ans<<endl;
	}
	return 0;
}