C :

#include <stdio.h>
#include <string.h>

int n, k, pi;
int list[1001], tmp[1001];
char optr;

int verify(){
  //printf("Verifying...\n");
  for(int i = 0; i < 2*pi; i++){
    //printf("Verified no.%d not to be fake.\n", tmp[i]);
    list[tmp[i]] = 1;
  }
}
int verifyRemains(){
  //printf("Verify Remains...\n");
  int i = 1, j = 1;
  for(i = 0; i < 2*pi; i++)
    if(list[tmp[i]] == 0)
      list[tmp[i]] = 2;
  for(i = 1; i <= n; i++){
    if(list[i] == 0){
      list[i] = 1;
      //printf("Verified no.%d not to be fake.\n", i);
    }
    else if(list[i] == 2)
      list[i] = 0;
  }
}
int check(){
  for(int i = 0; i < k; i++){
    scanf("%d", &pi);
    for(int j = 0; j < 2*pi; j++)
      scanf("%d", &tmp[j]);
    scanf(" %c", &optr);
    if(optr == '=') verify();
    else verifyRemains();
  }
  int res = 0;
  for(int i = 1; i <= n; i++){
    if(list[i] == 0){
      if(!res)
        res = i;
      else
        return 0;
    }
  }
  return res;
}
int main(){
  int i, j;
  scanf("%d%d",&n,&k);
  printf("%d\n", check());
  return 0;
}

C++ :

#include<cstdio>
#include<cstring>
#define N 1005
using namespace std;

int normal[N],light[N],heavy[N],tmp[N];

int main()
{
    memset(normal,0,sizeof(normal));
    memset(light,0,sizeof(light));
    memset(heavy,0,sizeof(heavy));
    //freopen("data.in","r",stdin);
    int n,k;
    int i,j,p;
    scanf("%d%d",&n,&k);
    for(i=0;i<k;i++)
    {
        int x;
        char ch;
        scanf("%d",&x);
        for(j=0;j<2*x;j++)
            scanf("%d",tmp+j);
        while((ch=getchar())!='='&&ch!='<'&&ch!='>');
        if(ch=='<')
        {
            for(j=0;j<x;j++)
                light[tmp[j]]=1;
            for(j=x;j<2*x;j++)
                heavy[tmp[j]]=1;
            for(j=1;j<=n;j++)
            {
                bool flag=true;
                for(p=0;p<2*x;p++)
                {
                    if(j==tmp[p])
                    {
                        flag=false;
                        break;
                    }
                }
                if(flag)
                    normal[j]=1;
            }
        }
        else if(ch=='=')
        {
            for(j=0;j<2*x;j++)
                normal[tmp[j]]=1;
        }
        else if(ch=='>')
        {
            for(j=0;j<x;j++)
                heavy[tmp[j]]=1;
            for(j=x;j<2*x;j++)
                light[tmp[j]]=1;
            for(j=1;j<=n;j++)
            {
                bool flag =true;
                for(p=0;p<2*x;p++)
                {
                    if(j==tmp[p])
                    {
                        flag=false;
                        break;
                    }
                }
                if(flag)
                    normal[j]=1;
            }
        }
    }
    int mark,count=0;
    for(i=1;i<=n;i++)
    {
        if(normal[i])
            continue;
        if(light[i]&&heavy[i])
            continue;
        mark=i;
        count++;
    }
    if(count>1)
        printf("0\n");
    else
        printf("%d\n",mark);
    return 0;
}