#include<bits/stdc++.h>
using namespace std;
using ll=long long;
using ull=unsigned long long;
const ll MOD=1000000000+7;
#define rep(I,N) for(int I=0;I<N;I++)
#define ALL(x) x.begin(),x.end()
#define PRINTV(x) for(auto i:x){for(auto j:i){printf("%d\t",j);}printf("\n");}
using vec = vector<int>;
using vvec = vector<vector<int>>;

ll lcm(ll a,ll b){
    return a/__gcd(a,b)*b;
}

int main(){
    string s;
    cin >> s;
    printf(s.size()==2?"Yes":"No");
}