#include <bits/stdc++.h>
int main() {
  int n, s[10001], ss[10001];
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%d", &s[i]);
  for (int i = 1; i < n; i++) {
    ss[i] = abs(s[i] - s[i + 1]);
  }
  ss[n] = abs(s[n] - s[1]);
  int t, min = 999999;
  for (int i = 1; i <= n; i++) {
    if (min > ss[i]) {
      min = ss[i];
      t = i;
    }
  }
  if (t != n)
    printf("%d %d\n", t, t + 1);
  else
    printf("%d %d\n", t, 1);
  return 0;
}
