#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int arr[n];
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }
  int min = INT_MAX;
  int idx1, idx2;
  for (int i = 0; i < n; i++) {
    if (abs(arr[i] - arr[(i + 1) % n]) < min) {
      min = abs(arr[i] - arr[(i + 1) % n]);
      idx1 = i;
      idx2 = (i + 1) % n;
    }
  }
  cout << idx1 + 1 << " " << idx2 + 1;
}
