简单模拟即可，如果有人接完水，就让下一个人上来接水，最后输出答案。

AC Code：

#include <bits/stdc++.h>
using namespace std;
int n, m, w[100005], ans;
int main()
{
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        cin >> w[i];
    int t = m + 1;
    while(t <= m + n)
    {
        for (int i = 1; i <= m; i++)
        {
            w[i]--;
            if (w[i] == 0)
            {
                w[i] = w[t];
                t++;
            }
        }
        ans++;
    }
    cout << ans;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
    //ios::sync_with_stdio(false);
    //cin.tie(0);
    long long n,m,a[10005],b[10005];
    cin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        cin >> a[i];
        b[i] = a[i];
    }
    for(int i = m + 1; i <= n; i++)
    {
        cin >> a[i];
        sort(b + 1,b + m + 1);
        b[1] += a[i];
    }
    sort(b + 1,b + m + 1);
    cout << b[m];
    return 0;
}