#include <algorithm>
#include <fstream>
using namespace std;
int x,i,k;
char s[25];
struct nod{
       int info;
       nod *a[30];
       nod(){info=0;
       for(int i=0;i<30;i++)
       a[i]=0;}
       } *p,*q,*inc;
int main ()
{ifstream f("trie.in");
 ofstream g("trie.out");
 inc=new nod();
while(f>>x>>s)
{p=inc;
if(x==0)
{
for(i=0;s[i];i++)
if(!p->a[s[i]-'a'])
{q=new nod();
p->a[s[i]-'a']=q;
p=q;
}
else
p=p->a[s[i]-'a'];
p->info++;}
else
if(x==1)
{for(i=0;s[i];i++)
p=p->a[s[i]-'a'];
p->info--;}
else
if(x==2)
{for(i=0;s[i];i++)
p=p->a[s[i]-'a'];
g<<(p->info)<<'\n';}
else
{k=0;
for(i=0;s[i];i++)
if(p->a[s[i]-'a'])
p=p->a[s[i]-'a']; 
else
break;
g<<i<<'\n';}
}
 f.close(); g.close();
return 0;
}