#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, x, s, index = 1, sum = 0, k = 1;
  cin >> n >> x;
  int a[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  for (int i = 0; i < x; i++) {
    sum += a[i];
  }
  s = sum;
  for (int i = x; i < n; i++) {
    if ((s + a[i] - a[k - 1]) < sum) {
      index = k + 1;
      sum = (s + a[i] - a[k - 1]);
    }
    s = s + a[i] - a[k - 1];
    ++k;
  }
  cout << index;
}
