#include <bits/stdc++.h>
using namespace std;
const long long N = 100005;
const long long MOD = 1e9 + 7;
int32_t main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n, i, x, fs, ss, ans;
  vector<long long> a;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> x;
    a.push_back(x);
  }
  ans = 1LL << 60;
  for (i = 0; i < n; i++) {
    if (abs(a[i] - a[(i + 1) % n]) < ans) {
      ans = abs(a[i] - a[(i + 1) % n]);
      fs = i;
      ss = (i + 1) % n;
    }
  }
  cout << fs + 1 << " " << ss + 1 << endl;
  return 0;
}
