program ded;
var a,b,m,n,f:integer;
BEGIN
writeln('vvedite a b'); readln(a,b);
m:=a; n:=b;
while m<>n do
if m>n then m:=m-n
else n:=n-m;
f:=m;
writeln('HOD(',a,',',b,')=',f);
readln;
END.