//Author: D. Nisritha Reddy
#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define ndl "\n"
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define mod (int)(1e9 + 7)
#define F first
#define S second
#define vi vector<int>
#define vc vector<char>
#define vpi vector<pair<int,int>>
#define pi pair<int,int>
#define mi map<int, int>
#define miv map<int,vector<int>>
using namespace std;

template<class T>
void inp(vector<T>&a){ for(auto &x : a)cin>>x; }

template<class T>
void print(vector<T>&a){
    for(auto &x: a)cout<<x<<" ";
    cout<<ndl;
}

template<class T>
void print(T x){cout<<x<<" ";}

template<class T>
void println(T x){ cout<<x<<"\n";}

template<class T>
T maxEle(vector<T>&a){
    T maxi = LLONG_MIN;
    for(auto x : a)
        if(x>maxi)maxi = x;
    return maxi;
}

template<class T>
T minEle(vector<T>&a){
    T mini = LLONG_MAX;
    for(auto x: a)
        if(x<mini) mini = x;
    return mini;
}

template<class T>
void sortAll(vector<T>&a){ sort(a.begin(), a.end());}

template<class T>
T sumAll(vector<T>&a){
    T sum = 0;
    for(auto x : a) sum +=x;
    return sum;
}

template<class T>
void revAll(vector<T>&a){reverse(a.begin(),a.end());}



///////////////////////////////////////////////////////////////////////////////////////////////////


int n, k;
vi a;

bool isPos(int mid){

    int sum = 0, grps = 1;

    for(int i = 0; i<n; i++){

        if(sum + a[i] > mid){
            sum = 0; grps++;
        }
        sum += a[i];
    }

    return grps <= k;

}

void solve(){

    cin>>n>>k;

    a.resize(n); inp(a);

    int l = maxEle(a), h = sumAll(a);
    int ans = 0;

    while(l<=h){

        int mid = ( l + h ) >> 1;

        if(isPos(mid)){
            ans = mid;
            h = mid - 1;
        }
        else{

            l = mid + 1;
        }


    }

    cout<<ans<<"\n";

}



///////////////////////////////////////////////////////////////////////////////////////////////////



signed main(){

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int t = 1; //cin>>t;
    while(t--){
        solve();
    }
}