34分求调

#include <iostream>
using namespace std;
const int N = 1e6 + 5;
long long a[N];
long long sum(int l, int r) {
    long long ans = 0;
    for (int i = l; i <= r; i++) {
        ans += a[i];
    }
    return ans;
}
int main(){
	int n , k;
	long long Sum = 0;
	long long max;
	cin >> n >> k;
	for ( int i = 1 ; i <= n ; i++ ){
		cin >> a[i];
	}
	for ( int i = 1 ; i <= n - k + 1; i++ ){
			Sum = sum( i , i + k - 1 );
			if ( i == 1 || max < Sum ){
				max = Sum;
			}
	}
	cout << max;
}