#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main(){
    ll n,m;cin>>n>>m;
    ll a[n];for(ll i=0;i<n;i++)cin>>a[i];
    ll sum[n+1];sum[0]=0;
    for(ll i=0;i<n;i++)sum[i+1]=sum[i]+a[i];
    ll l=-1,r=-1;
    for(;;){
        for(ll i=r+1;i<n;i++){
            if(a[i]%2==1){
                if(i==n-1&&i-l>=m){
                    cout<<sum[n]-sum[l+1]<<endl;
                    return 0;
                }
              if(i==n-1)return 0;
                continue;
            }
            else{
                if(i-l-1>=m){
                    cout<<sum[i]-sum[l+1]<<endl;
                }
                r=i;
                l=r;
                if(i==n-1)return 0;
                break;
            }
        }
    }
}