使用函数求奇数和

#include<stdio.h>
int even(int n)
{
  int z;
  if(n%2==0)
  z=1;
  else 
  z=0;
}
int main()
{
  int n,s=0,c;
  scanf("%d",&n);
  while(n>0)
  {
    c=even(n);
    if(c)
    {
      s+=n;
    }
    scanf("%d",&n);
  }
  printf("The sum of the odd numbers is %d",s);
}