#include <bits/stdc++.h>
using namespace std;
long long ans1 = 0, ans2 = 0;
int main() {
  long long n, i, j, k, l, m;
  cin >> n;
  long long a[n];
  for (long long i = 0; i < n; i++) cin >> a[i];
  long long mn = 1000000;
  for (i = 0; i < n - 1; i++) {
    if (abs(a[i] - a[i + 1]) < mn) {
      mn = abs(a[i] - a[i + 1]);
      ans1 = i + 1;
      ans2 = i + 2;
    }
  }
  if (abs(a[0] - a[n - 1]) < mn) {
    mn = abs(a[0] - a[n - 1]);
    ans1 = 1;
    ans2 = n;
  }
  cout << ans1 << " " << ans2 << endl;
}
