大佬救急！！！！

#include <stdio.h>
int feiyong(int hour,int length)
{
    float sum=0;
    if(hour>=5&&hour<=23)
    {
        if(length<=3)
        {
            sum=13+1;
        }
        else
        {
            sum=13+2.3*(length-3)+1;
        }
    }
    else if(hour<5&&hour>23)
    {
        if(length<=3)
        {
            sum=14;
        }
        else
        {
            sum=13+1.2*2.3*length+1;
        }
    }
    return sum;
}
int main()
{
    float s;
    s=feiyong(9,12)+feiyong(18,12);
    printf("小明打车需要%d元\n",s);
    return 0;
}
为啥我这个结果总是0