#include<string.h>
#include<iostream.h>

void main()
{
  char s1[200], s2[15], *p, aux[200];
  int cont=0;
  cin.get(s1,200);
  cin.get();
  cin>>s2;
  p=s1;
  while(strstr(p,s2))
  {  char *q=strstr(p,s2);
	 if(((q-1)[0]==' ' || p==s1) && (q+strlen(s2))[0]==' ')
	  { char aux[200];
		strcpy(aux,s2);
		strcat(aux,"?");
		strcat(aux,q+strlen(s2));
		strcpy(q,aux);
		cont=1;
	  }
      p=q+strlen(s2);
  }
  if(cont) cout<<s1;
  else cout<<"nu exista";
}