codeforces 467C George and Job dp

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long ll;
ll dp[5100][5100],sum[5100];
int n,m,k;
int main()
{
scanf("%d%d%d",&n,&m,&k);
int i,j,x;
sum[0]=0;
for(i=1;i<=n;i++)
{
scanf("%d",&x);
sum[i]=sum[i-1]+x;
}
memset(dp,0,sizeof(dp));
for(i=m;i<=n;i++)
for(j=1;j<=k;j++)
dp[i][j]=max(dp[i-1][j],dp[i-m][j-1]+sum[i]-sum[i-m]);
printf("%I64d\n",dp
[k]);
return 0;
}