#include <bits/stdc++.h>
using namespace std;
long long n, ans;
string str;
long long solve() {
  cin >> n;
  long long a[n];
  for (long long i = 0; i <= n - 1; ++i) cin >> a[i];
  long long t = abs(a[0] - a[n - 1]);
  for (long long i = 1; i <= n - 1; ++i) {
    t = min(t, abs(a[i] - a[i - 1]));
  }
  if (t == abs(a[0] - a[n - 1]))
    cout << 1 << " " << n;
  else {
    for (long long i = 1; i <= n - 1; ++i) {
      if (t == abs(a[i] - a[i - 1])) {
        cout << i << " " << i + 1;
        return 0;
      }
    }
  }
  return 0;
}
signed main() {
  ios::sync_with_stdio(0);
  long long t = 1;
  while (t--) solve();
  return 0;
}
