> #include <iostream>
> #include <algorithm>
> #include <stdio.h>
> #include <string.h>
> using namespace std;
> int n,m;
> int link[26][26];
> int in[26];
> struct node
> {
>     int num,p;
> }a[26];
> bool cmp(node a,node b)
> {
>     return a.num>b.num;
> }
> void init()
> {
>     memset(link,0,sizeof(link));
>     memset(in,0,sizeof(in));
>     int ii,way=0;
>     char st[10];
>     for(ii=1;ii<=m;ii++)
>     {
>         scanf("%s",st);
>         int s=st[0]-'A',t=st[2]-'A';
>         if(link[s][t]||s==t)
>         {
>             way=2;
>             break;
>         }
>         if(link[t][s])continue;
>         link[t][s]=1;
>         in[s]++;
>         for(int k=0;k<n;k++)
>         for(int i=0;i<n;i++)
>         for(int j=0;j<n;j++)
>         if(link[i][k]&&link[k][j]&&link[i][j]==0)
>         {
>             link[i][j]=1;
>             in[j]++;
>             if(link[j][i])
>             {
>                 way=2;
>                 goto XXX;
>             }
>         }
>         int num=0;
>         for(int i=0;i<n;i++)
>         for(int j=0;j<n;j++)
>         if(link[i][j]) num++;
>         if(num==n*(n-1)/2)
>         {
>             way=1;
>             for(int k=0;k<n;k++)
>             {
>                 a[k].p=k;
>                 a[k].num=in[k];
>             }
>             sort(a,a+n,cmp);
>             break;
>         }
> 
>     }
>     XXX:
>     if(way==2) printf("Inconsistency found after %d relations.\n",ii);
>     if(way==1)
>     {
>         printf("Sorted sequence determined after %d relations: ",ii);
>         for(int i=0;i<n;i++)printf("%c",'A'+a[i].p);
>         puts(".");
>     }
>     for(ii++;ii<=m;ii++)scanf("%s",st);
>     if(way==0) printf("Sorted sequence cannot be determined.\n");
> 
> }
> int main()
> {
>     //fr