#include <bits/stdc++.h>
using namespace std;
int diff = 0;
int differ(int a, int b) {
  int differ = 0;
  differ = a - b;
  if (differ < 0) {
    differ = differ * (-1);
  }
  return (differ);
}
int main() {
  long long int n, i, a[1000], a1 = 0, a2 = 0;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> a[i];
  }
  diff = differ(a[1], a[0]);
  for (i = 1; i < n; i++) {
    int d = differ(a[i], a[i - 1]);
    if (diff >= d) {
      diff = d;
      a1 = i;
      a2 = i + 1;
    }
  }
  int d1 = differ(a[n - 1], a[0]);
  if (diff >= d1) {
    a1 = n;
    a2 = 1;
  }
  cout << a1 << " " << a2;
  return (0);
}
