#include <bits/stdc++.h>
#define pb push_back
#define MAX 100000
#define mp make_pair
#define mod 1000000007
#define ll long long
#define ull unsigned long long
#define fastio ios_base::sync_with_stdio(NULL),cin.tie(NULL),cout.tie(NULL);
#define FILES freopen("trie.in","r",stdin);\
              freopen("trie.out","w",stdout);
using namespace std;
int nodes,op;
string a,s;
struct Trie
{
    int Go[30],fr[30];
    bool isEnd;
};
vector<Trie> Tree;
void Insert(string a)
{
    int s = 0;
    for(int i = 0;i < a.size(); ++i)
    {
        int nex = Tree[s].Go[a[i]-'a'];
        if(!nex)
        {
            Tree.pb(Trie());
            nodes++;
            Tree[s].Go[a[i]-'a'] = nodes;
            Tree[s].fr[a[i]-'a']++;
            s = nodes;
        }
        else
            Tree[s].fr[a[i]-'a']++,s = nex;
    }
    Tree[s].isEnd = 1;
}
void Delete(string a)
{
    int s = 0,cnt = 0;
    for(int i = 0;i < a.size(); ++i)
    {
        int nex = Tree[s].Go[a[i]-'a'];
        if(!Tree[s].fr[a[i]-'a']) return;
        s = nex;
    }
    s = 0;
    for(int i = 0;i < a.size(); ++i)
    {
        int nex = Tree[s].Go[a[i]-'a'];
        Tree[s].fr[a[i]-'a']--;
        s = nex;
    }
}
inline int Occur(string a)
{
    int s = 0,ans = 1e9;
    for(int i = 0;i < a.size(); ++i)
    {
        ans = min(ans,Tree[s].fr[a[i]-'a']);
        s = Tree[s].Go[a[i]-'a'];
    }
    for(int i = 'a';i <= 'z'; ++i)
        ans -= Tree[s].fr[i-'a'];
    if(ans < 0) ans = 0;
    return ans;
}
inline int prefix(string a)
{
    int s = 0, l = 0;
    for(int i = 0;i < a.size(); ++i)
    {
        if(Tree[s].fr[a[i]-'a'])
            l++;
        else break;
        s = Tree[s].Go[a[i]-'a'];
    }
    return l;
}
int main()
{
    fastio
    FILES
    Tree.pb(Trie());
    while(getline(cin,s))
    {
        a.clear();
        op = s[0] - '0';
        for(int j = 2;j < s.size(); ++j)
            a += s[j];
        if(!op) Insert(a);
        else if(op == 1)
            Delete(a);
        else if(op == 2)
            cout << Occur(a) << '\n';
        else
            cout << prefix(a) << '\n';
    }
}