#include <iostream>
#include <fstream>

using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");

int v[100005];
bool test(int d, int n, int k){
    int t=1;
    int s=0;
    for(int i=1;i<=n;i++){
        if(v[i]+s<=d){
            s=s+v[i];
        }
        else{
            s=v[i];
            t++;
        }
    }
    return t<=k;
}

int binsearch(int st, int dr, int n, int k){
    int ans=-1;
    while(st<=dr){
        int med=(st+dr)/2;
        if(test(med,n,k)==true){
            dr=med-1;
            ans=med;
        }
        else{
            st=med+1;
        }
    }
    return ans;
}
int main()
{
    int n,k,maxim=-1;
    fin>>n>>k;
    for(int i=1;i<=n;i++){
        fin>>v[i];
        if(v[i]>maxim)
            maxim=v[i];
    }
    fout<<binsearch(maxim,100000000,n,k);
    return 0;
}