please help me. for this problem I get 50 out of 100 points.
#include <iostream>
using namespace std;
int t[1000001],n,k;
long long sv=0,sn=0;
int main()
{
cin>>n>>k;
for(int i=1;i<=n;++i)
cin>>t[i];
for(int i=0;i<k;++i)
sv+=t[i];
for(int i=1;i<=n-k+1;++i)
{
sn=0;
for(int j=i;j<i+k;++j)
{
sn+=t[j];
}
if(sn>sv)
sv=sn;
}
cout<<sv;
return 0;
}