#include <bits/stdc++.h>
using namespace std;
const int lim = 1e5 + 5;
int main(int argc, char const *argv[]) {
  int n;
  cin >> n;
  std::vector<int> v(n);
  for (int i = 0; i < n; ++i) {
    cin >> v[i];
  }
  int mn = INT_MAX, ind1, ind2;
  for (int i = 0; i < n - 1; ++i) {
    int dif = abs(v[i] - v[i + 1]);
    if (mn > dif) {
      mn = dif;
      ind1 = i + 1;
      ind2 = i + 2;
    }
  }
  int dif = abs(v[0] - v[n - 1]);
  if (mn > dif) {
    mn = dif;
    ind1 = 1;
    ind2 = n;
  }
  cout << ind1 << " " << ind2 << endl;
  return 0;
}
