Here is my source!

#include <stdio.h>
int main(){
char ch;
int sumall=0;
while (!feof(stdin)) {scanf("%c",&ch); if (feof(stdin))
break;sumall+=ch-48;}
//printf("s=%d",sumall);
printf("%d\n",(sumall%3==0)+1);
if (sumall%3) printf("%d",sumall%3);
return 0;
}

Thanks!!!

#include <stdio.h>
int main(){
char ch;
int sumall=0;
while (!feof(stdin)) {scanf("%c",&ch);
if (feof(stdin)) break;
if (ch>='0' && ch<='9')sumall+=(ch-'0');}<---check at this :)
sumall%=3;
printf("%d",((sumall==0)+1));
if (sumall) printf("\n%d",sumall);
return 0;
}

Als0, we can use sumall+=ch instead of sumall+=(ch-'0'), because '0' == 0x30 == 3*16 :)