Thanks for the help, apparently that was the problem at first. Then when I tried to run it, I got a bunch of errors. What I had to do was upload the source file and recompile it. Dunno why, seeing...
I wrote and compiled a program on a unix machine using g++. Now I copied it over to the machine with the Unix emulator Cygwin. I tried to run it by entering "a.out" in the command prompt but was...