#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int minans = 1000000;
  pair<int, int> p;
  int n;
  cin >> n;
  int a[n];
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  for (int i = 1; i < n; i++) {
    if (abs(a[i] - a[i - 1]) < minans) {
      minans = abs(a[i] - a[i - 1]);
      p.first = i;
      p.second = i + 1;
    }
  }
  if (abs(a[n - 1] - a[0]) < minans) {
    minans = abs(a[n - 1] - a[0]);
    p.first = n;
    p.second = 1;
  }
  cout << p.first << " " << p.second;
  return 0;
}
