#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e2 + 10;
int diff = 1e9;
int main() {
  int r, l;
  int n;
  cin >> n;
  int arr[maxn];
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }
  arr[n] = arr[0];
  for (int i = 1; i <= n; i++) {
    if (abs(arr[i] - arr[i - 1]) < diff) {
      diff = abs(arr[i] - arr[i - 1]);
      r = i;
      l = i - 1;
    }
  }
  if (r == n) {
    r = 0;
  }
  r++;
  l++;
  cout << l << " " << r << endl;
}
