#include<bits/stdc++.h>
#define ll long long int
using namespace std;

ll maxPage(ll *P, const int &n)
{
	ll maxi = -1;
	for(int i = 0; i < n; i++)
	{
		if(P[i] > maxi)
		{
			maxi = P[i];
		}
	}
	return maxi;
}

ll sumPages(ll *P, const int &n)
{
	ll sum = 0;
	for(int i = 0; i <n; i++)
		sum += P[i];
	return sum;
}

int numParts(ll *P, const int &n, ll maxSize)
{
	int k = 1;
	ll sum = 0;
	for(int i = 0; i < n; i++)
	{
		sum += P[i];
		if(sum > maxSize)
		{
			k++;
			sum = P[i];
		}
	}
	return k;
}

ll bin_part(ll *P, const int &n, const int &m)
{
	int k;
	ll low = maxPage(P, n);
	ll high = sumPages(P, n);
	ll mid;
	while(low < high)
	{
		mid = low + (high - low)/2;
		k = numParts(P, n, mid);
		if(k <= m)
		{
			high = mid;
		}
		else
		{
			low = mid + 1;
		}
	}
	return low;
}

int main()
{
	int n, m;
	cin>>n;
	ll P[n];
	for(int i = 0; i < n; i++)
		cin>>P[i];
	cin>>m;
	ll ans = bin_part(P, n, m);
	cout<<ans<<endl;
	return 0;
}