#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, pre, f, min, index1, index2, x;
  cin >> n;
  cin >> f;
  cin >> x;
  pre = x;
  min = abs(f - pre);
  index1 = 1, index2 = 2;
  for (int a = 2; a < n; a++) {
    cin >> x;
    if (min > abs(x - pre)) min = abs(x - pre), index1 = a, index2 = a + 1;
    pre = x;
  }
  if (min > abs(x - f)) index1 = 1, index2 = n;
  cout << index1 << " " << index2 << endl;
  return 0;
}
