#include <bits/stdc++.h>
using namespace std;
int n, a[101], nxt, l, h;
int main(int argc, const char* argv[]) {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
  }
  int mn = 10001;
  for (int i = 0; i < n; i++) {
    nxt = i + 1;
    nxt %= n;
    if (mn > abs(a[i] - a[nxt])) {
      mn = abs(a[i] - a[nxt]);
      l = i;
      h = nxt;
    }
  }
  printf("%d %d\n", l + 1, h + 1);
  return 0;
}
