为什么就是不对???

# include<stdio.h>
void main()
{

int max(int a,int b,int c);
int a,b,c,n;
scanf("%d%d%d",&a,&b,&c);
n=max(a,b,c);
printf("the largest is %d\n",n);
}
int max(int a,int b,int c)
{
int z;
if(a>c) c=a;
if(b>c) c=b;
z=c;
return z;

}