#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[105];
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  a[n] = a[0];
  int k;
  int minn = 10005;
  for (int i = 1; i <= n; i++) {
    if (abs(a[i] - a[i - 1]) < minn) {
      minn = abs(a[i] - a[i - 1]);
      k = i;
    }
  }
  if (k >= n) {
    cout << 1 << " " << k << endl;
  } else {
    cout << k + 1 << " " << k << endl;
  }
}
