正解是 $2$，我的是 $3$。

#include<bits/stdc++.h>
#define ll long long
using namespace std;
namespace Mashiro {
    char buf[1<<18],*p1=buf,*p2=buf;
    inline int getc() {
        return p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<18,stdin),p1==p2)?EOF:*p1++;
    }
    template<typename T>inline void read(T& x) {
        x=0;int f=1;
        char ch=getc();
        while(!isdigit(ch)){if(ch=='-')f=~f+1;ch=getc();}
        while (isdigit (ch)) {x=(x<<3)+(x<<1)+(ch^48);ch=getc();}
        x*=f;
    }      
    template <typename T,typename... Args> inline void read(T& x, Args&... args) {
        read(x);
        read(args...);
    }
    char buffer[1<<18];int p11=-1;const int p22=(1<<18)-1;
    inline void flush() {fwrite(buffer,1,p11+1,stdout),p11=-1;}
    inline void putc(const char &x) {if (p11==p22) flush();buffer[++p11]=x;}
    template<typename T>inline void write(T x) {
        static int buf[40],top=0;
        if(x<0)putc('-'),x=~x+1;
        while(x)buf[++top]=x%10,x/=10;
        if(top==0)buf[++top]=0;
        while (top) putc(buf[top--]^48);
        putc(' ');
        flush();
     }
     template <typename T,typename... Args> inline void write(T x, Args... args) {
         write(x);
         write(args...);
     }
}
using namespace Mashiro;
const int maxst=(1<<10)+2;
int dp[maxst];
int nxt[105][maxst],vis[maxst];
int a[105][12];
int n,m;
int main() {
    read(n,m);
    for(int i(1);i<=m;++i){
        for(int j(1);j<=n;++j){
            read(a[i][j]);
        }
    }
    int St=(1<<n)-1;
    for(int i(0);i<=St;++i){
        for(int j(1);j<=m;++j){
            int temp=i;
            for(int k(0);k<n;++k){
                if(a[j][k+1]==1&&(temp&(1<<k)))temp^=(1<<k);
                else if(a[j][k+1]==-1&&!(temp&(1<<k)))temp^=(1<<k);
            }
            nxt[j][i]=temp;
            //cout<<(bitset<4>)i<<" "<<(bitset<4>)temp<<" "<<j;
            //cout<<endl;
        }
    }
    memset(dp,0x3f,sizeof dp);
    dp[St]=0;
    queue<int>q;
    q.push(St);
    while(!q.empty()){
        int u=q.front();
        q.pop();
        if(u==0)break;
        for(int i(1);i<=m;++i){
            if(vis[nxt[i][u]])continue;
            dp[nxt[i][u]]=dp[u]+1;
            q.push(nxt[i][u]);
            vis[nxt[i][u]]=1;
        }
    }
    if(!vis[0])write(-1);
    else write(dp[0]);
#ifndef ONLINE_JUDGE
    cout<<endl;
    system("pause");
#endif
    return 0;
}