#include <stdio.h>
int main(){
    int units;
    float bill=0.0;
    scanf("%d",&units);
}
if(units<=0){
    printf("Invalid input");
    return 0;
}
if(units<=100){
    bill=unit*0.10;
}
else if (units<=200){
    bill=(100*0.10) + (units -100) * 0.15;
}
else{
    bill = (100*0.10 = (100*0.15) = (units-200) *0.20;
}

printf("%.2f", bill);
return 0;
}
}