#include <fstream>
using namespace std;
typedef long long ll;
ifstream cin("transport.in");
ofstream cout("transport.out");
ll numere[160001],n,k;
bool verif(int cap)
{
    ll sum = 0 , sol = 1;
    for(int i = 1;i<=n;i++)
    {
        if(sum+numere[i]<=cap)
            sum+=numere[i];
        else
            sum = numere[i],sol++;
    }
    return (sol<=k);
}

int main()
{
    ll sum = 0,maxi=0
    cin>>n>>k;
    for(int i = 1;i<=n;i++)
    {
        cin>>numere[i];
        if(numere[i]>maxi)
            maxi = numere[i];
        sum+=numere[i];
    }
    ll st = maxi , dr = sum;
    ll sol = 0;
    while(st<=dr)
    {
        int mid = st + (dr-st)/2;
        if(verif(mid))
            sol = mid , dr = mid-1;
        else
            st = mid+1;
    }
    cout<<sol;
    return 0;
}