#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  int min = 100000, id, id_1;
  for (int i = 0; i < n - 1; i++) {
    if (abs(a[i + 1] - a[i]) < min) {
      min = abs(a[i + 1] - a[i]);
      id_1 = i + 2;
      id = i + 1;
    }
  }
  if (abs(a[0] - a[n - 1]) < min)
    cout << "1 " << n << endl;
  else
    cout << id_1 << " " << id << endl;
  return 0;
}
