文件目录

#include <iostream>
#include <sstream>
using namespace std;
int main()
{
    string s, a, b, c;
    getline(cin, s);
    cin >> a >> b;
    istringstream ss(s);
    while (ss >> c)
    {
        if (c == a)
            cout << b << " ";
        else
            cout << c << " ";
    }
    return 0;
}