#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, i, k, j, h, c, l = 0, p = 0;
  cin >> n;
  vector<int> v, t;
  for (i = 0; i < n; i++) {
    cin >> k;
    v.push_back(k);
  }
  p = abs(v[0] - v[n - 1]);
  h = 0;
  c = n - 1;
  l = p;
  for (i = 1; i < n; i++) {
    p = abs(v[i] - v[i - 1]);
    if (p < l) {
      l = p;
      h = i;
      c = i - 1;
    }
  }
  printf("%d %d", h + 1, c + 1);
}
