#include <bits/stdc++.h>
using namespace std;
void solve() {
  int n;
  int s[n];
  cin >> n;
  int x = n;
  int y = 1;
  for (int i = 0; i < n; i++) cin >> s[i];
  int best = abs(s[n - 1] - s[0]);
  for (int i = 0; i < n - 1; i++) {
    if (abs(s[i] - s[i + 1]) < best) {
      best = abs(s[i] - s[i + 1]);
      x = i + 1;
      y = i + 2;
    }
  }
  cout << x << " " << y << '\n';
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int t;
  t = 1;
  while (t--) solve();
  return 0;
}
