#include<iostream>
using namespace std;

int main(){
    float a,b,c;
    while(cin>>a){
                  if(0.01<=a<100.00)
                  b=(a*0.9)+8;
                  if(a==100.00)
                  b=a*0.9;
                  if(100.01<=a<=500.00)
                  b=a*0.8;
                  if(a>=500.01)
                  b=a*0.6;
                 
                 
                  b=b*100;
                  b=(int)b;
                  b=(float)b;
                  b=b/100;
                  cout<<"$"<<b<<endl;
                  //printf("%.2f",b);
                 
                  }
    system("pause");
    return 0;
}

為什麼會WA?