#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
const int mod = 1e9 + 7;
ll n,m;
vector<char>a[1000006];
int fa[10000005];
// 初始化
void init(int n)
{
    for (int i = 1; i <= n; i++)
        fa[i] = i;
}

// 找父节点，路径压缩
int find(int i)
{
    if (fa[i] == i)
        return i;
    else
    {
        fa[i] = find(fa[i]); // 路径压缩
        return fa[i];
    }
}
// 合并
void bing(int i, int j)
{
    int i_fa = find(i);
    int j_fa = find(j);
    fa[i_fa] = j_fa;
}
ll quickp(ll a,ll b){
    ll ans = 1;
    while(b > 0){
        if(b&1){
            ans = ans * a %mod;
        }
        b >>= 1;
        a = a*a%mod;
    }
    return ans%mod;
}
void solve()
{

    cin >> n >> m;
    init(n);
    for(int i = 1;i <= n;i++){
        a[i].clear();
        a[i].push_back(0);
        for(int j = 1;j <= m;j++){
            char x;cin >> x;
            a[i].push_back(x);
        }
    }   
    // cout << a[1][2] << "?";

    for(int j = 1;j <= (m-1)/2+1;j++){
        ll cnt1 = 0;
        ll x,y;
        for(int i = 1;i <= n;i++){
            if(a[i][j] == '1'){
                cnt1++;
                if(cnt1 == 1)x = i;
                if(cnt1 == 2)y = i;
                if(cnt1 > 2){
                    cout << "0\n";
                    return ;
                }
            }
        }
        // cout << "cnt " << cnt1 << "\n";
        for(int i = 1;i <= n;i++){
            if(a[i][m-j+1] == '1'){
                cnt1++;
                if(cnt1 == 1)x = i;
                if(cnt1 == 2)y = i;
                if(cnt1 > 2){
                    cout << "0\n";
                    return ;
                }
            }
        }
        if(cnt1 == 2)
            bing(x,y);
    }
    ll cnt2=0;
    for(int i = 1;i <= n;i++){
        if(fa[i] == i){
            cnt2++;
        }
    }
    cout << quickp(2,cnt2) << "\n";
   
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
 

answer.code: In function ‘int main()’:
answer.code:102:17: error: expected ‘}’ at end of input
  102 |     cout.tie(0);
      |                 ^
answer.code:99:1: note: to match this ‘{’
   99 | {
      | ^