不知道哪里有错，咋办啊

#include <stdio.h>
int main(void)
{
int a,b,max,ret;
printf("Input a, b:");
ret = scanf("%d,%d,&a,&b);
if (ret != 2);
{
printf("Input data quantity or format error!\n");
fflush(stdin);
}
else
{
max = a > b? a:b;
printf("max = %d\n",max);
}
return 0;
}

int main(void)
{
int a,b,max,ret,l;
printf("Input a, b:");
scanf("%d%d",&a,&b);
l=a;
ret=b;
if (ret != 2 and l!=2)
{
printf("Input data quantity or format error!\n");
fflush(stdin);
}
else
{
max = a > b? a:b;
printf("max = %d\n",max);
}
return 0;
}