#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  std::ios_base::sync_with_stdio(false);
  long long int n, x[100], minn = INT_MAX, ii, jj;
  cin >> n;
  for (long long int i = 0; i < n; i++) {
    cin >> x[i];
  }
  for (long long int i = 0; i < n - 1; i++) {
    if (abs(x[i] - x[i + 1]) < minn) {
      minn = abs(x[i] - x[i + 1]);
      ii = i;
      jj = i + 1;
    }
  }
  if (abs(x[0] - x[n - 1]) < minn) {
    ii = 0;
    jj = n - 1;
  }
  ii++, jj++;
  cout << ii << " " << jj << endl;
  return 0;
}
