#include <assert.h>
#include <stdio.h>

int main()
{
    for (int i = 0; i < 2; i++) {
        FILE *file = fopen("/sandbox/input.txt", "r");
        assert(file != NULL);

        char c = fgetc(file);
        while (c != EOF) {
            assert(fputc(c, stdout) != EOF);
            c = fgetc(file);
        }
    }
}