#include <stdio.h>
#include <stdlib.h>
int v[16000];
int main(){
    FILE*fi,*fout;
    int st,dr,i,k,n,m,con,s,min,max,max1;
    fi=fopen("transport.in" ,"r");
    fout=fopen("transport.out" ,"w");
    fscanf(fi,"%d%d" ,&n,&k);
    for(i=0;i<n;i++)
      fscanf(fi,"%d" ,&v[i]);
    st=1;
    dr=256000000;
    min=256000000;
    while(dr-st>=1){
        m=(st+dr)/2;
        con=1;
        s=max=0;
        for(i=0;i<n;i++)
            if(s+v[i]<=m)
                s=s+v[i];
            else{
                con++;
                if(s>max)
                    max=s;
                s=v[i];
            }
        if(con<=k)
            dr=m-1;
        else
            st=m+1;
    }
    m=(st+dr)/2;
    con=1;
    s=max1=0;
    for(i=0;i<n;i++)
        if(s+v[i]<=m)
            s=s+v[i];
        else{
            con++;
            if(s>max1)
                max1=s;
            s=v[i];
        }
    if(con>k)
        max1=max;
    if(max>max1)
        max=max1;
    fprintf(fout,"%d" ,max);
    fclose(fi);
    fclose(fout);
    return 0;
}