#include <bits/stdc++.h>
using namespace std;
int arr[111];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%d", &arr[i]);
  }
  int ans = 0x7fffffff;
  int ansi, ansj;
  for (int i = n, j = 1; j <= n; i = j++) {
    if (abs(arr[i] - arr[j]) < ans) {
      ans = abs(arr[i] - arr[j]);
      ansi = i;
      ansj = j;
    }
  }
  printf("%d %d\n", ansi, ansj);
  return 0;
}
