看不懂題目在*嗎

只比尾數就得到 AC  冏

/***********************************************************/

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
main()
{
  char ANS[1000],M[1000];
   while(gets(ANS))
       {
          int SUM=0,m=strlen(ANS);
          if(ANS[0]=='0'&&m==1) break;
          while(gets(M))
              {
                 int n=strlen(M);
                 if(M[0]=='0'&&n==1) break;
                  SUM+=M[n-1];
              }
          ANS[m-1]%=2;
                if(SUM%2==ANS[m-1])
                  {
                    if(ANS[m-1]==0) puts("1");
                    else puts("2");
                  }
                else puts("0");
       }
    return 0;
}