#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x[100000], a, c = 10000, z, y;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> x[i];
  }
  for (int i = 0; i < n; i++) {
    if (i != n - 1)
      a = (x[i + 1] - x[i]) > 0 ? (x[i + 1] - x[i]) : (-(x[i + 1] - x[i]));
    else
      a = (x[0] - x[i]) > 0 ? (x[0] - x[i]) : (-(x[0] - x[i]));
    if (a < c) {
      c = a;
      z = i + 1;
      y = i + 1 == n ? 1 : i + 2;
    }
  }
  cout << z << " " << y;
  return 0;
}
