#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x, k;
  cin >> n;
  int a[n];
  vector<pair<int, int> > v;
  for (int i = 0; i < n; i++) cin >> a[i];
  for (int i = 0; i < n - 1; i++) {
    x = abs(a[i] - a[i + 1]);
    v.push_back(make_pair(x, i + 1));
  }
  v.push_back(make_pair(abs(a[0] - a[n - 1]), n));
  sort(v.begin(), v.end());
  k = v[0].second;
  if (k < n)
    cout << k << " " << k + 1;
  else
    cout << 1 << " " << k;
  return 0;
}
