#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  int n;
  cin >> n;
  vector<int> arr(n);
  for (auto &el : arr) cin >> el;
  arr.push_back(arr[0]);
  int mn = numeric_limits<int>::max(), mni;
  for (int i = 0; i < n; ++i) {
    if (abs(arr[i + 1] - arr[i]) < mn) {
      mn = abs(arr[i + 1] - arr[i]);
      mni = i;
    }
  }
  if (mni == n - 1)
    cout << mni + 1 << ' ' << 1 << endl;
  else
    cout << mni + 1 << ' ' << mni + 2 << endl;
  return 0;
}
