#include "bits/stdc++.h"
using namespace std;
vector<vector<vector<vector<int>>>> dp;
vector<int> a, b;
int solve(int A, int B, int c, int d) {
if (A == (int) a.size() && B == (int) b.size() && c == 0 && d == 0) {
return 0;
}
vector<int> upda, updb;
if (A < a.size()) upda = {A};
if (B < b.size()) updb = {B};
if (dp[A][B][c][d] == (int) -2e9) {
for (auto i : upda) {
dp[A][B][c][d] = max(dp[A][B][c][d], -(a[i] - 4) - solve(A + 1, B, c, d + 1));
}
for (auto i : updb) {
auto tc = c, td = d;
int L = b[i] / 2, R = b[i] - L, res = 0;
if (L >= 2) {
tc++;
res += L - 2;
} else if (L) {
res++;
}
if (R >= 2) {
tc++;
res += R - 2;
} else if (R) {
res++;
}
dp[A][B][c][d] = max(dp[A][B][c][d], -res - solve(A, B + 1, tc, td));
}
if (c) {
dp[A][B][c][d] = max(dp[A][B][c][d], abs(2 + solve(A, B, c - 1, d)));
}
if (d) {
dp[A][B][c][d] = max(dp[A][B][c][d], abs(4 + solve(A, B, c, d - 1)));
}
}
return dp[A][B][c][d];
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, m;
cin >> n >> m;
auto get = [&] (int i, int j) {
return i * m + j;
};
auto check = [&] (int i, int j) {
return (i >= 0 && i < n && j >= 0 && j < m);
};
vector<vector<int>> g(n * m);
vector<int> cnt(n * m, 4);
auto add = [&] (int a, int b, int c, int d) {
if (check(a, b)) {
cnt[get(a, b)]--;
}
if (check(c, d)) {
cnt[get(c, d)]--;
}
if (check(a, b) && check(c, d)) {
g[get(a, b)].push_back(get(c, d));
g[get(c, d)].push_back(get(a, b));
}
};
for (int i = 0; i < n + 1; i++) {
for (int j = 0; j < m; j++) {
char c;
cin >> c;
if (c == '0') {
add(i - 1, j, i, j);
}
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < m + 1; j++) {
char c;
cin >> c;
if (c == '0') {
add(i, j - 1, i, j);
}
}
}
vector<int> used(n * m);
int c = 0, was;
function<void(int)> dfs = [&] (int v) {
used[v] = 1;
if ((int) g[v].size() == 1) {
was = 1;
}
c++;
for (auto u : g[v]) {
if (!used[u]) {
dfs(u);
}
}
};
vector<int> A, B, C, D;
for (int i = 0; i < n * m; i++) {
if (cnt[i] != 4 && !used[i]) {
c = 0, was = 0;
dfs(i);
if (was || c == 1) {
B.push_back(c);
} else {
A.push_back(c);
}
}
}
sort(A.begin(), A.end());
sort(B.begin(), B.end());
a = A, b = B;
dp.resize((int) a.size() + 1, vector<vector<vector<int>>> ((int) b.size() + 1, vector<vector<int>> ((int) b.size() * 2 + 1,
vector<int> ((int) a.size() + 1, -(int) 2e9))));
cout << solve(0, 0, 0, 0);
}
