#include <fstream>
using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");
const int nmax=16000;
int v[nmax+5],n,k;
bool ok(int cap)
{
int tr,sc,i;
sc=tr=0;
for(i=1;i<=n;i++)
{
if(v[i]>cap)
return 0;
if(sc+v[i]<=cap)
sc=sc+v[i];
else
{
tr++;
sc=v[i];
}
}
if(sc>0)
tr++;
return tr<=k;
}
int bs_left(int st, int dr)
{
int med,last=-1;
while(st<=dr)
{
med=(st+dr)/2;
if(ok(med))
{
last=med;
dr=med-1;
}
else
st=med+1;
}
return last;
}
int main()
{
int i,s;
fin>>n>>k;
s=0;
for(i=1;i<=n;i++)
{
fin>>v[i];
s=s+v[i];
}
fout<<bs_left(1,s);
fin.close();
fout.close();
return 0;
}