#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;

const int MAXN=100000;
const int INF=1<<25;
int a[MAXN];
int N,M;

/*
flase 代表mid的取值太小
true  代表mid的取值太大
*/
bool cal(int mid){
    int sum=0;
    int cnt=0;
    for(int i=0;i<N;i++){
        if(a[i]>mid)
            return false;
        if(sum+a[i]>mid){
            cnt++;
            sum=0;
        }
        sum+=a[i];
    }
    if(sum>0)
        cnt++;
    if(cnt<=M)
        return true;
    else
        return false;
}

int main(){
    cin>>N>>M;
    int sum=0;
    int Max=-INF;
    for(int i=0;i<N;i++){
        scanf("%d",&a[i]);
        Max=max(Max,a[i]);
        sum+=a[i];
    }

    if(N==M){
        cout<<Max<<endl;
        return 0;
    }
    if(M==1){
        cout<<sum<<endl;
        return 0;
    }

    int L=0,R=sum;
    while(R-L>1){
        int mid=(L+R)>>1;
        if(cal(mid)){
            R=mid;
        }else{
            L=mid;
        }
    }
    cout<<R<<endl;
    return 0;
}