#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");

int v[100005];
bool incape(int dimensiune, int n, int k){
    int nrTransporturi=1;
    int s=0;
    for(int i=1;i<=n;i++){
        if(v[i]+s<=dimensiune)
            s=s+v[i];
        else{
            s=v[i];
            nrTransporturi++;
        }
    }
    return nrTransporturi<=k;
}
int binsearch(int st, int dr,int n,int k){
    int ans=-1;
    while(st<=dr){
        int med=(st+dr)/2;
        if(incape(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,128000000,n,k);

    return 0;
}