#include <bits/stdc++.h>
using namespace std;
const int Maxn = 110;
int num[Maxn];
int main() {
  int n;
  int i, j, k;
  scanf("%d", &n);
  for (i = 1; i <= n; i++) scanf("%d", &num[i]);
  int l = 1, r = n, mmin = abs(num[1] - num[n]);
  for (i = 1; i < n; i++) {
    if (mmin > abs(num[i] - num[i + 1])) {
      mmin = abs(num[i] - num[i + 1]);
      l = i, r = i + 1;
    }
  }
  printf("%d %d\n", l, r);
  return 0;
}
