#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (cin >> n) {
    vector<int> v(n);
    for (auto& i : v) cin >> i;
    int mmin = 1001;
    int s1, s2 = 0;
    for (int i = 0; i < n - 1; i++) {
      if (mmin > abs(v[i] - v[i + 1])) {
        s1 = i + 1;
        s2 = i + 2;
        mmin = abs(v[i] - v[i + 1]);
      }
    }
    if (mmin > abs(v[0] - v[n - 1])) {
      s1 = n;
      s2 = 1;
    }
    cout << s1 << " " << s2 << endl;
  }
  return 0;
}
