main()
{ int z;

if (x>y)
z=x;
else
z=y;
return(z);
}
main()
{
int n1,n2;
printf("input the frist number:")
scanf("%d",&n1);
printf("nput the second number:")
scanf("%d",&n2);
printf("max=%d\n",max(n1,n2));
}

xiexie  ,!!!