#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#pragma GCC optimize("unroll-loops")
using namespace std;
double eps = 1e-12;
void solve() {
  int n;
  cin >> n;
  int a[n];
  int minn = INT_MAX, l, r;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  for (int i = 1; i < n; i++) {
    if (minn > abs(a[i] - a[i - 1])) {
      minn = abs(a[i] - a[i - 1]);
      l = i + 1;
      r = i;
    }
  }
  if (minn > abs(a[0] - a[n - 1])) {
    minn = abs(a[0] - a[n - 1]);
    l = 1;
    r = n;
  }
  cout << l << " " << r << endl;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  solve();
  return 0;
}
