#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long int n, ans = INT_MAX, idx1, idx2;
  cin >> n;
  long long int a[n + 1];
  for (long long int i = 0; i < n; i++) cin >> a[i];
  a[n] = a[0];
  for (long long int i = 0; i < n + 1; i++) {
    if (abs(a[i + 1] - a[i]) < ans) {
      ans = abs(a[i + 1] - a[i]);
      idx1 = i + 1, idx2 = i + 2;
    }
  }
  if (idx2 > n) idx2 = idx2 % n;
  cout << idx1 << " " << idx2;
  return 0;
}
