#include <bits/stdc++.h>
using namespace std;
int main() {
  int *l;
  int n;
  cin >> n;
  l = new int[n];
  for (int i = 0; i < n; i++) cin >> l[i];
  int min = 0;
  for (int i = 1; i < n - 1; i++)
    if (abs(l[i + 1] - l[i]) < abs(l[min + 1] - l[min])) min = i;
  if (abs(l[0] - l[n - 1]) < abs(l[min + 1] - l[min]))
    cout << "1 " << n;
  else
    cout << min + 1 << " " << min + 2;
  return 0;
}
