#include<cstdio>
#include<iostream>
#include<queue>
#include<cstring>
#include<algorithm>
#include<cctype>
using namespace std;
typedef long long ll;
const int INF=1e9;
const int N=2010,M=N*N*2;
inline int read(){int X=0,w=0;char ch=0;while(!isdigit(ch)){w|=ch=='-';ch=getchar();}while(isdigit(ch))X=(X<<3)+(X<<1)+(ch^48),ch=getchar();return w?-X:X;
}
inline int getc(){char ch=0;while(!isdigit(ch))ch=getchar();return ch^48;
}
struct node{int nxt,to,w,b;
}edge[M];
int head[N],cnt=-1;
inline void add(int u,int v,int w,int b){edge[++cnt].to=v;edge[cnt].w=w;edge[cnt].b=b;edge[cnt].nxt=head[u];head[u]=cnt;edge[++cnt].to=u;edge[cnt].w=0;edge[cnt].b=-b;edge[cnt].nxt=head[v];head[v]=cnt;
}
int dis[N];
bool vis[N];
inline bool spfa(int s,int t,int n){deque<int>q;memset(vis,0,sizeof(vis));for(int i=1;i<=n;i++)dis[i]=INF;dis[t]=0;q.push_back(t);vis[t]=1;while(!q.empty()){int u=q.front();q.pop_front();vis[u]=0;for(int i=head[u];i!=-1;i=edge[i].nxt){int v=edge[i].to;int b=edge[i].b;if(edge[i^1].w&&dis[v]>dis[u]-b){dis[v]=dis[u]-b;if(!vis[v]){vis[v]=1;if(!q.empty()&&dis[v]<dis[q.front()]){q.push_front(v);}else{q.push_back(v);}}}}}return dis[s]<INF;
}
int ans,cur[N];
int dfs(int u,int flow,int m){if(u==m){vis[m]=1;return flow;}int res=0,delta;vis[u]=1;for(int &e=cur[u];e!=-1;e=edge[e].nxt){int v=edge[e].to;int b=edge[e].b;if(!vis[v]&&edge[e].w&&dis[u]-b==dis[v]){delta=dfs(v,min(edge[e].w,flow-res),m); if(delta){edge[e].w-=delta;edge[e^1].w+=delta;res+=delta;ans+=delta*b;if(res==flow)break;}}}return res;
}
int sum1=0,sum2=0;
inline int costflow(int S,int T,int n){int flow=0;while(spfa(S,T,n)){do{for(int i=1;i<=n;i++)cur[i]=head[i];memset(vis,0,sizeof(vis));flow+=dfs(S,INF,T);}while(vis[T]);}if(flow!=sum1||sum1!=sum2)return -1;return ans;
}
int dx[8]={0,1,0,-1,1,1,-1,-1};
int dy[8]={1,0,-1,0,1,-1,-1,1};
bool mp[21][21][2];
int main(){memset(head,-1,sizeof(head));int n=read(),m=read(),S=m*n*3+1,T=S+1;for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){mp[i][j][0]=getc();int now=(i-1)*m+j;if(mp[i][j][0]){sum1++;add(S,now+m*n,1,0);}}}for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){mp[i][j][1]=getc();int now=(i-1)*m+j;if(mp[i][j][1]){sum2++;add(now+m*n,T,1,0);}}}for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){for(int k=0;k<8;k++){int nx=i+dx[k],ny=j+dy[k];if(nx<1||nx>n||ny<1||ny>m)continue;int pre=(i-1)*m+j,now=(nx-1)*m+ny;add(pre+2*m*n,now,INF,1);}}}for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){int ch=getc(),now=(i-1)*m+j;if(mp[i][j][0]){add(now,now+m*n,ch/2,0);add(now+m*n,now+2*m*n,(ch+1)/2,0);}else if(mp[i][j][1]){add(now,now+m*n,(ch+1)/2,0);add(now+m*n,now+2*m*n,ch/2,0);}else{add(now,now+m*n,ch/2,0);add(now+m*n,now+2*m*n,ch/2,0);}}}printf("%d\n",costflow(S,T,T));return 0;
}