CCF认证 2013-12 ISBN号码

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
using namespace std;
int main()
{
string s;
cin>>s;
int sum=0,cnt=1;
for(int i=0;i<11;i++)
if(s[i]=='-') continue;
else sum+=(s[i]-'0')*cnt++;
int t=s[12]-'0';
if(s[12]=='X') t=10;
sum%=11;
if(sum==t) printf("Right\n");
else
{
s.erase(12,1);
if(sum==10) s+='X';
else s+='0'+sum;
cout<<s<<endl;
}
return 0;
}