#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int ara[n];
  for (auto i = 0; i < n; i++) cin >> ara[i];
  int ind = 0, ind1 = 1;
  int tmp = 0;
  int diff = abs(ara[1] - ara[0]);
  for (auto i = 2; i < n; i++) {
    if (diff > abs(ara[i] - ara[i - 1])) {
      diff = abs(ara[i] - ara[i - 1]);
      ind1 = i;
      ind = i - 1;
    }
  }
  if (diff > abs(ara[n - 1] - ara[0])) {
    diff = abs(ara[n - 1] - ara[0]);
    ind1 = n - 1;
    ind = 0;
    tmp = 1;
  }
  tmp == 1 ? cout << ind1 + 1 << " " << ind + 1
           : cout << ind + 1 << " " << ind1 + 1;
  return 0;
}
