var a, b, с: integer;
begin
write('Введите два числа: ');
readln(a, b);
if a < b then с := a + 1 else с := b + 1;
repeat с := с - 1
until (a mod с = 0) and (b mod с = 0);
write('NOD = ', с)
end.
//2. Алгоритм с вычитанием (цикл while)
var a, b: integer;
begin
write('a = ');
readln(a);
write('b = ');
readln(b);
while a <> b do
if a > b then
a := a - b
else
b := b - a;
writeln('NOD = ', a);
end.
x1, y1, x2, y2, x3, y3, x4, y4=list(map(lambda x:int(x),input('(x1, y1), (x2, y2), (x3, y3), (x4, y4)\n').split()))
a,b,c,d=((x2-x1)**2+(y2-y1)**2)**0.5,((x3-x2)**2+(y3-y2)**2)**0.5,((x4-x3)**2+(y4-y3)**2)**0.5,((x4-x1)**2+(y4-y1)**2)**0.5
if(a==b % c==d):
print(a*d)
elif(a==c,b==d):
print(a*b)
else:
print("не прямоугольник")