Var
p: array[1..2, 1..2] of real;
d: real;
i: integer;
begin
for i := 1 to 2 do begin
write('x', i , '=');
readln(p[i,1]);
write('y', i , '=');
readln(p[i,2]);
end;
d := sqrt(sqr(p[1,1] - p[2,1]) + sqr(p[1,2] - p[2,2]));
writeln('расстояние = ', d:0:3);
end.