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program pr1;
var a, b, m,: integer;
p: real;
begin
m: =0;
readln (a,b);
p: = b-a;
if p mod 2 = 0 then
m: = p/2;
end;
if p mod 2 = 1 then
m: =(p-1)/2;
writeln(m);
end.

source.pas(4,13) fatal: syntax error, "identifier" expected but ": " found
error: /usr/bin/ppcx64 returned an error exitcode