#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int arr[n];
  for (int i = 0; i < n; i++) cin >> arr[i];
  int a, b;
  int min = INT_MAX;
  for (int i = 0; i < n - 1; i++)
    if (abs(arr[i] - arr[i + 1]) < min)
      min = abs(arr[i] - arr[i + 1]), a = i, b = i + 1;
  if (abs(arr[n - 1] - arr[0]) < min) a = n - 1, b = 0;
  cout << a + 1 << " " << b + 1;
  return 0;
}
