#include
using namespace std;
const int maxn = 100005;
int n, m, l, r;
int a[maxn];
inline bool check(int x){
int tot = 0, cnt = 0;
for(int i = 1; i <= n; ++i){
if(tot + a[i] <= x) tot += a[i];
else tot = a[i], ++cnt;
}
return cnt >= m;
}
int main(){
cin >> n >> m;
for(int i = 1; i <= n; ++i) cin >> a[i], l = max(l, a[i]), r += a[i]; //l为何不能从0开始二分？？？
while(l <= r){
int mid = l + r >> 1;
if(check(mid)) l = mid + 1;
else r = mid - 1;
}
cout << l;
return 0;
}
