#include<bits/stdc++.h>

using namespace std;

int main()
{
	string s;
	cin>>s;
	string a = "black",b = "block";
	int p = s.find(a);
	while(p != string::npos)
	{
		/*s.erase(p,5);
		s.insert(p,b);
		*/
		s.replace(p,5,b);
		p = s.find(a);
	}
	cout<<s<<endl;
	return 0;
}