If i used
readln(a);
readln(b);
readln(c);
I got WA on test #12
if i used
read(a);
read(b);
read(c);
i pass that test
What the?

faint!!

me too!!

IMHO:
readln() reads EOLN from input buffer (eq. 0x13 or 0x10)
From problem:
"Each of the three input lines contains an integer..."
but third line of file may contain EOF (no EOLN) at end and this don't reads by readln(); may be there are mistake...
But I use C++ and I also can have errors in Pascal...

p.s. Sorry for my English.