#include <stdio.h>
int main(){
float x,y;
int b;
scanf("%f",&x);
if(-5<x&&x<0){
b=1;
}else if(x==0){
b=2;
}else if(0<x&&x<8){
b=3;
}
switch (b)
{
case 1: y=x*x-1;break;
case 2: y=x;break;
case 3: y=x+1;break;
default:printf("请重新输入");
}
printf("y=%f",y);
return 0;
}