#include <bits/stdc++.h>
#include <assert.h>
using namespace std;
const long long MOD1 = 1000000007;
const long long MOD2 = 998244353;
#define logn long
#define lnog long
#define lgon long
#define itn int
typedef long long ll;
typedef pair<long long, long long> P;
const long long INF = 1e18;
int main(){
    string S; cin >> S;
    if (S.size() == 2) cout << "Yes" << endl;
    else cout << "No" << endl;
}