var y,x:real;
begin
writeln('введите x');
readln(x);
if (x>0) and (x<=1) then y:=sqrt(x+2) else if (x>1)then Y:=ln(x-1) else y:=17.9+x;
writeln(y)
end.
var y,x:real;
begin
writeln('введите x');
readln(x);
if (x>0) and (x<=1) then y:=sqrt(x+2) else if (x>1)then Y:=ln(x-1) else y:=17.9+x;
writeln(y)
end.