Problem:
Score : 100 points

Problem Statement

In AtCoder City, there are three stations numbered 1, 2, and 3.

Each of these stations is operated by one of the two railway companies, A and B. A string S of length 3 represents which company operates each station. If S_i is A, Company A operates Station i; if S_i is B, Company B operates Station i.

To improve the transportation condition, for each pair of a station operated by Company A and one operated by Company B, there will be a bus service connecting them.

Determine if there is a pair of stations that will be connected by a bus service.

Constraints

Each character of S is A or B.

|S| = 3

Input

Input is given from Standard Input in the following format:

S

Output

If there is a pair of stations that will be connected by a bus service, print Yes; otherwise, print No.

Sample Input 1

ABA

Sample Output 1

Yes

Company A operates Station 1 and 3, while Company B operates Station 2.

There will be a bus service between Station 1 and 2, and between Station 2 and 3, so print Yes.

Sample Input 2

BBA

Sample Output 2

Yes

Company B operates Station 1 and 2, while Company A operates Station 3.

There will be a bus service between Station 1 and 3, and between Station 2 and 3, so print Yes.

Sample Input 3

BBB

Sample Output 3

No

Company B operates all the stations. Thus, there will be no bus service, so print No.

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

// When you are hungry for something and you're determined and you're focused 
// and you're committed to something it's hard to surrender, isn't it?

#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(), (x).end()
#define endl "\n"
#define ll long long 
#define int ll
#define mod 1000000007
#define mod1 1000000006
#define modi 998244353
#define setbit(x) __builtin_popcount(x)
#define ff first
#define ss second
#define pb push_back
vector<ll> vi[300005];
int color[100005];
ll pa[500005];
ll si[500005];
#define pb push_back
bool visi[1000005]={false};
bool is[100005];
ll fac[10000001];
ll prime[400005];
ll bit[100005];
const long double eps = 1.0e-14;      // allowable error
#define fio ios_base::sync_with_stdio(false); cin.tie(NULL);
 
 
void fact(){
    fac[0]=1;
    for(int i=1;i<=10000000;i++){
        fac[i]=(fac[i-1]*i)%mod;
    }
    return ;
}
void sieve(){
    prime[0]=0;
    prime[1]=0;
    for(int i=2;i<400005;i++){
        prime[i]=1;
    }
    for(int i=2;i*i<400005;i++){
        if(prime[i]==1){
            for(int j=i*i;j<400005;j+=i){
                prime[j]=0;
            }
        }
    }
    
}
 
ll power(ll n , ll p ){
    if(p==0)
        return 1;
    
    ll res = power((n*n)%mod,p/2);
    if(p%2==1)
        res = (n*res)%mod;
    
    return res;
}
 
 
void upd(ll i,ll val,ll n) {
    for(;i<=n;i+=i&(-i))
        bit[i]+=val;
}
 
ll qry(ll i) {
    ll sum=0;
    for(;i>0;i-=i&(-i))
        sum+=bit[i];
    return sum;
}
 
 
ll fin(ll u) {
    if(pa[u]==u)
        return u;
    return fin(pa[u]);
}
 
void uni(ll u,ll v) {
    ll p1=fin(u);
    ll p2=fin(v);
    if(p1==p2)
        return;
    if(si[p1]<si[p2])
        swap(p1,p2);
    si[p1]+=si[p2];
    pa[p2]=p1;
    return;
}
 
int32_t main() {
    fio
    
    string s;
    cin >> s;
    
    if((s[0]==s[1] or s[0]==s[2] or s[1]==s[2]) and (s[0]!=s[1] or s[0]!=s[2] or s[1]!=s[2]))
        cout << "Yes" << endl;
        else
        cout << "No" << endl;
	return 0;
    
}