#include <bits/stdc++.h>
using namespace std;
#define bokusunny ios::sync_with_stdio(false), cin.tie(nullptr);

void solve() {
  string S;
  cin >> S;

  if ((int)S.size() == 2) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}

int main() {
  bokusunny;
  solve();

  return 0;
}