关于#ar#的问题，如何解决？

#include
int main()
{
char ch;
long m=0, n, nx = 0;
while (ch = getchar() != '\n')
{
if (ch >= '0' && ch <= '9')
m = m * 10 + ch - 0;
else
putchar(ch);
}
n = m;
while (n != 0)
{
nx = nx * 10 + m % 10;
m = m / 10;
}
printf("\n%ld reverse number is %ld\n", n, nx);
return 0;
}

while ((ch = getchar()) != '\n')
m = m * 10 + ch - '0';