#include <bits/stdc++.h>
using namespace std;
int main() {
  int m = 100000, n, arr[1000], i, index;
  cin >> n;
  for (i = 0; i < n; i++) cin >> arr[i];
  for (i = 0; i < n - 1; i++) {
    if (abs(arr[i] - arr[i + 1]) < m) {
      m = abs(arr[i] - arr[i + 1]);
      index = i;
    }
  }
  if (abs(arr[n - 1] - arr[0]) < m) {
    m = abs(arr[n - 1] - arr[0]);
    index = i;
  }
  if (index == n - 1)
    cout << index + 1 << ' ' << 1;
  else
    cout << index + 1 << ' ' << index + 2;
  return 0;
}
