56 2 (7)

#include <iostream>
#include <fstream>

using namespace std;

int main()
{

    ifstream in1("in1.txt");
    ifstream in2("in2.txt");
    ofstream out("output.txt");
    while (in1.peek() != EOF)
    {
        int cur;
        in1 >> cur;
        if (cur > 0)
            out << cur << ' ';
    }
    while (in2.peek() != EOF)
    {
        int cur;
        in2 >> cur;
        if (cur < 0)
            out << cur << ' ';
    }

}