а)
var a,b:integer;
begin
read(a,b);
repeat
if a>b then
a:=a-b
else
b:=b-a;
until (a=b);
write(a);
end.
б)
while (a<>b) do
а)
var a,b:integer;
begin
read(a,b);
repeat
if a>b then
a:=a-b
else
b:=b-a;
until (a=b);
write(a);
end.
б)
var a,b:integer;
begin
read(a,b);
while (a<>b) do
if a>b then
a:=a-b
else
b:=b-a;
write(a);
end.