Well, it would seem that you cannot run the file because it is not in your path.
By that I simply mean the computer does not know where to look for it. If you are in the same directory as your compiled program, you will first want to ensure that the file is executable. To do a listing of the program with its permision, try:
in the list look for your program, you should see permisions...
r - read
w - write
x - execute
If the permision is missing for a given file a '-' will act as a place holder. If you do not have 'x' for the file you will need to add the exectuable permision, one way to do this is to...
chmod +x strasse
after this re-run the listing command...
You should now see the 'x' permision in three places (a story for a diffrent day).
Now lets try to run the program. Before the file you wish to run place a dot & slash to signify that you want to run the file in the current directory, such as...
This should avoid the problem of the computer not finding your file.