This is my code,I can't find mistakes, but it keeps WA:

program zxx(input,output);
var temp,p,q:extended;
    i,n:integer;
    f:boolean;
begin
   read(p,q);
   if q<p then begin temp:=q;q:=p;p:=temp end;
   p:=p/100;q:=q/100;
   i:=0;
   f:=false;
   repeat
       i:=i+1;
       if (trunc(i*p+1)<=trunc(i*q)) or (trunc(i*p)=i*p) or (trunc(i*q)=i*q) then f:=true;
   until(f);
   write(i);
end.