#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<int> v;
  pair<int, int> ans;
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    v.push_back(x);
  }
  int c = 1e9;
  for (int i = 0; i < n - 1; i++) {
    if (abs(v[i] - v[i + 1]) < c) {
      c = abs(v[i] - v[i + 1]);
      ans = {i, i + 1};
    }
  }
  if (abs(v[0] - v[n - 1]) < c) {
    ans = {0, n - 1};
  }
  cout << ans.first + 1 << " " << ans.second + 1 << endl;
}
