iiitv/ChefLib

// Code written by Monal
#include "bits/stdc++.h"
#include <stdio.h>

using namespace std;

#define li long int
#define in(a) cin>>a
#define out(a) cout<<a<<"\n"
#define pb(a) push_back(a)
#define forn(n) for (int i = 0; i < n; ++i)

vector < string > yes;
vector < string > no;
vector <string > answer;

template <typename Container>
bool LexCompare(const Container& a, const Container& b) {
    return lexicographical_compare(a.begin(), a.end(), b.begin(), b.end());
}

// Use that comparison function to sort a range:
template <typename ContainerIterator>
void sort_by_lexicographical_comapre(ContainerIterator beg, ContainerIterator end) {
    sort(beg, end, LexCompare<typename ContainerIterator::value_type>);
}


string calculate(string check, vector<string> yes) {
    for (int i = 1; i <= check.length(); ++i) {
        int j;
        string temp = check.substr(0,i);
        for (j = 0; j < yes.size(); ++j) {
            if (i > yes[j].length())
                continue;
            if (temp == yes[j].substr(0,i))
                break;
        }
        if (j == yes.size())
            return temp;
    }
    return "NO";
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    in(n);
    char ch;
    string s;
    forn(n) {
        in(ch);
        in(s);
        if (ch == '+')
            yes.pb(s);
        else
            no.pb(s);
    }
    forn(no.size()) {
        string temp = calculate(no[i],yes);
        if (temp != "NO")
            answer.pb(temp);
    }
    if (answer.size() != no.size()) {
        cout<<"-1";
        return 0;
    }
    set<string> myset( answer.begin(), answer.end() );
    answer.assign( myset.begin(), myset.end() );
    out(answer.size());
    forn(answer.size()) {
        out(answer[i]);
    }
    return 0;
}