排队打水

#include<iostream>
#include<cstdio>
#include<queue>
#include<vector>
#include<algorithm>
#include<cstring>
using namespace std;
int n,m;
int a[100009];
priority_queue<long long >q;
long long x;
int main()
{
    freopen("death.in","r",stdin);
    freopen("death.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
        scanf("%d",&a[i]);
    
    for(int i=1;i<=m;i++)
    q.push(-a[i]);
    
    for(int i=m+1;i<=n;i++)
    {
        x=q.top();q.pop(); 
        x-=1LL*a[i];
        q.push(x);
    } 
    
    cout<<-q.top();
    return 0;
}