#include <iostream>
#include <cstring>
using namespace std;
char s[256];

int main()
{
    cin.getline(s, 256);
    int n;
    cin >> n;
    bool ok = 0;
    char* p = strtok(s, " ");
    while (p)
    {
        int val = strlen(p);
        if (n == val)
            ok = 1, cout << p << "\n";
        p = strtok(NULL, " ");
    }
    if (ok == 0)
        cout << "nu exista";
    return 0;
}