#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
int n,k;
vector<ll>a;
bool check(ll x){
    int c=1;
    ll s=0;
    for(int i=0;i<n;i++){
        s+=a[i];
        if(s>x){
            c++;
            s=a[i];
        }
    }
    return c<=k;
}
int main(){
    fast;
    cin>>n>>k;
    a.resize(n);
    ll l=0,r=0;
    for(int i=0;i<n;i++){
        cin>>a[i];
        l=max(l,a[i]);
        r+=a[i];
    }
    ll ans=r;
    while(l<=r){
        ll mid=l+(r-l)/2;
        if(check(mid)){
            ans=mid;
            r=mid-1;
        }else{
            l=mid+1;
        }
    }
    cout<<ans;
    return 0;
}