////有一组函数：y=x (x<1)
////y=2*x-1 (1<=x<10)
////y=3*x-11
Console.Write("x=");
double x = double.Parse(Console.ReadLine());
double y;
if (x < 1)
{
Console.WriteLine("y=" + x);
}
if (x >= 1 && x < 10)
{
y = 2 * x - 1;
Console.WriteLine(y);
}
else
{
y = 3 * x - 11;
Console.WriteLine(y);
}