55 1 (7)

#include <iostream>
#include <string>
#include <fstream>

using namespace std;

int main()
{
    char c;
    cin >> c;
    ifstream in("input.txt");
    while (in.peek() != EOF)
    {
        string s;
        getline(in, s);
        if (s[0] == c)
            cout << s << endl;
    }

}