#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint = modint1000000007;
//using mint = modint998244353;
//std::chrono::time_point<std::chrono::steady_clock> start;
template <typename T> bool chmax(T &u, const T z) { if (u < z) {u = z; return true;} else return false; }
template <typename T> bool chmin(T &u, const T z) { if (u > z) {u = z; return true;} else return false; }
#define ll long long
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
typedef pair<ll, int> P;
ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : x; }
ll lcm(ll a, ll b){return a * b / gcd(a, b);}
template<class T, class U>
//contain(string s,string v) sにvが含まれるかを判定
bool contain(const std::basic_string<T>& s, const U& v) {
   return s.find(v) != std::basic_string<T>::npos;
}
std::chrono::time_point<std::chrono::steady_clock> start;

int main(){
  string s;
  cin>>s;
  if(s.size()==2)cout<<"Yes"<<endl;
  else cout<<"No"<<endl;
  return 0;

}