#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
const int MAXN=1e5+10;
int a[MAXN],s[MAXN];
int N,M;
bool check(int x){
    int tot=1;
    int l=0;
    int r=1;
    while(r<=N){
        while(s[r]-s[l]<=x) r++;
        tot++;
        l=r;
        if(tot>M) return false;
    }
    return true;
}
int main(){
    scanf("%d%d",&N,&M);
    for(int i=1;i<=N;i++){
        scanf("%d",&a[i]);
        s[i]=s[i-1]+a[i];
    }
    int mid,l=0,r=1e9;
    while(l<r){
        mid=l+r>>1;
        if(check(mid)) r=mid;
        else l=mid+1;
    }
    cout<<l<<endl;
    return 0;
}