C语言数字总和程序

#include<stdio.h>
 int main()  
{  
int n,sum=0,m;  
printf("Enter a number:");  
scanf("%d",&n);  
while(n>0)  
{  
m=n%10;  
sum=sum+m;  
n=n/10;  
}  
printf("Sum is=%d",sum);  
return 0;
} 

Enter a number:654
Sum is=15
Enter a number:123
Sum is=6