#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n, ans = 1e9, c, d;
  cin >> n;
  int a[n];
  cin >> a[0];
  for (int i = 1; i < n; i++) {
    cin >> a[i];
    if (abs(a[i] - a[i - 1]) < ans) {
      c = i;
      d = i + 1;
      ans = abs(a[i] - a[i - 1]);
    }
  }
  if (abs(a[0] - a[n - 1]) < ans)
    cout << n << " " << 1 << endl;
  else
    cout << c << " " << d << endl;
}
