// Problem: No.2599 Summer Project
// Contest: yukicoder
// URL: https://yukicoder.me/problems/no/2599
// Memory Limit: 512 MB
// Time Limit: 2000 ms

#include<bits/stdc++.h>
#define debug(x) cerr<<(#x)<<" "<<(x)<<endl
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
#define pii pair<ll,ll>
#define rep(i,a,b) for(ll i=(a);i<=(b);++i)
#define per(i,a,b) for(ll i=(a);i>=(b);--i)
using namespace std;
bool Mbe; 
ll read(){
	ll x=0,f=1;char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
	return x*f;
}
void write(ll x){
	if(x<0)putchar('-'),x=-x;
	if(x>9)write(x/10);
	putchar(x%10+'0');
}
map<string,ll>mp;
bool Med;
int main(){
	cerr<<fabs(&Med-&Mbe)/1048576.0<<"MB\n";
	mp["beachball"]=mp["watermelon"]=mp["shrinebell"]=0;
	string s;cin>>s;mp[s]=1;cin>>s;mp[s]=1;
	for(pair<string,ll>p:mp){
		if(!p.second)cout<<p.first;
	}
	return 0;
}