Простая C++ задача. Проблема с циклом while

Почему x, y, z равны нулю?

#include <iostream> 
#include <cmath>
int main() 
{ 
    int day = 3; 
    double x = 1, y = 1, z = 1, now, sum = 3; 
 

    while (sum < 1000) { 
     
        now = floor((0.5 * z + 0.25 * y + 0.15 * x)*100)/100; 
        x = y; y = z; z = now;
        sum = sum + now; 
     
        day ++ ; 
    
        std::cout << x << " " << y << " " << z << std::endl;
 
    } 
 
    std::cout << day/365; 
}