#include <bits/stdc++.h>
int main() {
  int n, h[300], i, j, min, p, q, temp;
  scanf("%d", &n);
  for (i = 0; i < n; i++) scanf("%d", &h[i]);
  temp = h[1] - h[0];
  if (temp < 0) temp = -temp;
  min = temp;
  p = 0;
  q = 1;
  for (i = 0; i < n; i++) {
    j = i + 1;
    if (j == n) j = 0;
    temp = h[i] - h[j];
    if (temp < 0) temp = -temp;
    if (temp < min) {
      min = temp;
      p = i;
      q = j;
    }
  }
  printf("%d %d\n", p + 1, q + 1);
  return 0;
}
