Don't know why I am getting WA...Here is my code.... #include<stdio.h> #include<string.h> int main() { long long i,j,k,s; char n[1000]; while(1) { s=0; scanf("%s",&n); i=strlen(n); if(n[0]=='0' && n[1]=='\0') break; for(j=0;j<i;j++) { s=s*10+n[j]-'0'; } if(s%11==0) printf("...