整数各位数字求和

#include <stdio.h>
int sum(int x)
{
	int sum=0,a;
	while(x!=0)
	{
		a=x%10;
		sum=sum+a;
		x=x/10;
	}
	return sum;
}
int main()
{
	int x,s;
	scanf("%d",&x);
	s=sum(x);
	printf("%d\n",s);
	return 0;
}