#include <bits/stdc++.h>
const double EPS = 1e-12;
const long long MAX = 1e6 + 10;
const long long MOD = 1e9 + 7;
using namespace std;
int main() {
  int soldiers;
  cin >> soldiers;
  int heights[100];
  for (int i = 0; i < soldiers; i++) {
    cin >> heights[i];
  }
  int minimum = 2147483647;
  int p1, p2;
  p1 = p2 = 0;
  for (int i = 0; i < soldiers; i++) {
    if (abs(heights[i] - heights[i + 1]) < minimum) {
      p1 = i + 1;
      p2 = i + 2;
      minimum = abs(heights[i] - heights[i + 1]);
    }
  }
  if (abs(heights[0] - heights[soldiers - 1]) < minimum) {
    p1 = 1;
    p2 = soldiers;
  }
  cout << p1 << " " << p2 << endl;
}
