Disturbing math problem with Arduino. Overflow?

hi!

i've stumbled upon problem cant figure out cause of.
this little code snippet test program pretty sums i'm having hard time figuring out:

 long b = 255000;
 serial.println(b);
 long = 1000*255;  // 1000 * 255 = 255000 //
 serial.println(a);
 delay(1000);

the serial output of 'b' is: 255000
while serial output 'a' is: -7144

could please explain me why happens?
i first stumbled upon when tried use map function. when returned '0' started looking , above couldn't further on own.


thanks!

-rindis

what :

code: [select]

long = 1000l*255l;
give?

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