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*******************************************************************************/

#include <fstream>
using namespace std;
int v[16005];
ifstream cin("transport.in");
ofstream cout("transport.out");
int main()
{
    int n, k, s=0, ss, mij, st, dr, ans=400000009, cnt, maxs;
    cin>>n>>k;
    for(int i=1; i<=n; i++)
    {
        cin>>v[i];
        s+=v[i];
        maxs=max(maxs,v[i]);
    }
    st=maxs;
    dr=s+1;
    while(st<=dr)
    {
        mij=(st+dr)/2;
        ss=0;
        cnt=0;
        for(int i=1; i<=n; i++)
        {
            ss+=v[i];
            if(ss+v[i]>mij*cnt)
                cnt++;
        }
        if(cnt<=k)
        {
            ans=mij;
            dr=mij-1;
        }
        else st=mij+1;
    }
    cout<<ans;

    return 0;
}