#include <bits/stdc++.h>
using namespace std;
char s1[100000000];

int main() {
	long long n,a=0;
	cin>>s1;
	for(int i=0; i<strlen(s1); i++) {
		if(s1[i]>='a'&&s1[i]<='z'||s1[i]>='A'&&s1[i]<='Z') {
			cout<<s1[i];
		}
	}
	return 0;
}