#include <bits/stdc++.h>
int main() {
  int arr[1000], n, i, j, k, counter = 99999999, x, y;
  scanf("%d", &n);
  for (i = 0; i < n; ++i) {
    scanf("%d", &arr[i]);
  }
  for (j = 1; j < n; ++j) {
    for (k = j - 1; k < j; ++k) {
      if (abs(arr[j] - arr[k]) < counter) {
        counter = abs(arr[j] - arr[k]);
        x = j + 1;
        y = k + 1;
      }
    }
  }
  if (abs(arr[0] - arr[n - 1]) < counter) {
    counter = abs(arr[0] - arr[n - 1]);
    x = 1;
    y = n;
  }
  printf("%d %d", y, x);
  return 0;
}
