#include <bits/stdc++.h>
using namespace std;
const double pi = 2.0 * acos(0.0);
const double eps = 1.0e-9;
const int dr[] = {-1, 0, 1, 0}, dc[] = {0, 1, 0, -1};
const int dr6[] = {1, 1, 0, -1, -1, 0}, dc6[] = {0, 1, 1, 0, -1, -1};
const int dr8[] = {-1, -1, 0, 1, 1, 1, 0, -1},
          dc8[] = {0, 1, 1, 1, 0, -1, -1, -1};
int main(void) {
  int kase = 1000000000;
  for (int ks = 1, n, a[128]; ks <= kase && cin >> n; ++ks) {
    for (int i = 0; i < n; ++i) cin >> a[i];
    a[n] = a[0];
    int least = 1000000000;
    for (int i = 0; i < n; ++i) least = min(least, abs(a[i] - a[i + 1]));
    for (int i = 0; i < n; ++i)
      if (least == abs(a[i] - a[i + 1])) {
        cout << (i + 1) << " " << ((i + 1) % n + 1) << endl;
        break;
      }
  }
  return 0;
}
