#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n + 5];
  for (int i = 1; i <= n; i++) cin >> a[i];
  int m = 1;
  for (int i = 2; i < n; i++) {
    if (abs(a[i] - a[i + 1]) < abs(a[m] - a[m + 1])) m = i;
  }
  if (abs(a[n] - a[1]) < abs(a[m] - a[m + 1])) {
    cout << n << " " << 1;
  } else
    cout << m << ' ' << m + 1 << endl;
}
