#include <bits/stdc++.h>
using namespace std;
const int N = 105;
int n, arr[N];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }
  int fmin = 1000000;
  int ans1, ans2;
  for (int i = 0; i < n; i++) {
    int g = abs(arr[i] - arr[(i + 1) % n]);
    if (g < fmin) {
      fmin = g;
      ans1 = i;
      ans2 = (i + 1) % n;
    }
  }
  cout << ans1 + 1 << " " << ans2 + 1 << '\n';
  return 0;
}
