#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, p1, p2, temp;
  int mn = INT_MAX;
  cin >> n;
  int a[n + 1];
  for (i = 0; i < n; i++) cin >> a[i];
  a[n] = a[0];
  for (i = 0; i < n; i++) {
    temp = abs(a[i] - a[i + 1]);
    if (temp < mn) {
      mn = temp;
      p1 = i;
      if (i + 1 == n)
        p2 = 0;
      else
        p2 = i + 1;
    }
  }
  cout << p1 + 1 << " " << p2 + 1;
  return 0;
}
