What is wrong in this code?

Question

https://code.sololearn.com/ck87C8V0cfsA/?ref=app

Answer 1

If you just wanted to add all digits then this will work fine.

#include<stdio.h>

int main()
{
int a,b,s=0;
scanf("%d",&a); // missing &
while(a>0)
{
b=a%10;
a/=10;
s+=b;
}

printf("%d",s);
return 0;
}

Answer 2

Then also it is not working