#include <bits/stdc++.h>
using namespace std;
int dfs(pair<int, int> init, pair<int, int> p, int x, int y, vector<string> &H, vector<string> &V, vector<vector<int>> &occ, int N, int M, vector<int> &ones, vector<int> &fours, vector<int> &eights)
{
occ[x][y] = 1;
int tot = 1;
if ((x > 0 && occ[x - 1][y] && H[x][y] == '0' && !(p.first == x - 1 && p.second == y)) || (x < N - 1 && occ[x + 1][y] && H[x + 1][y] == '0' && !(p.first == x + 1 && p.second == y)) || (y > 0 && occ[x][y - 1] && V[x][y] == '0' && !(p.first == x && p.second == y - 1)) || (y < M - 1 && occ[x][y + 1] && V[x][y + 1] == '0' && !(p.first == x && p.second == y + 1)))
return -1;
if (x > 0 && H[x][y] == '0' && !occ[x - 1][y])
tot += dfs(init, {x, y}, x - 1, y, H, V, occ, N, M, ones, fours, eights);
if (x < N - 1 && H[x + 1][y] == '0' && !occ[x + 1][y])
tot += dfs(init, {x, y}, x + 1, y, H, V, occ, N, M, ones, fours, eights);
if (y > 0 && V[x][y] == '0' && !occ[x][y - 1])
tot += dfs(init, {x, y}, x, y - 1, H, V, occ, N, M, ones, fours, eights);
if (y < M - 1 && V[x][y + 1] == '0' && !occ[x][y + 1])
tot += dfs(init, {x, y}, x, y + 1, H, V, occ, N, M, ones, fours, eights);
if ((tot == 1 || tot == 2) && init.first == x && init.second == y)
{
if (H[x][y] == '1' && H[x + 1][y] == '1' && V[x][y] == '1' && V[x][y + 1] == '1')
tot = 0;
else
ones.push_back(-tot);
return 0;
}
if (init.first == x && init.second == y)
{
if (tot < 1)
eights.push_back(tot - 2);
else
fours.push_back(-tot);
}
if (tot < 1)
return tot - 2;
return tot;
}
int main()
{
int N, M;
cin >> N >> M;
vector<string> V(M + 1), H(N + 1);
for (int i = 0; i <= N; i++)
cin >> H[i];
for (int i = 0; i < N; i++)
cin >> V[i];
vector<vector<int>> occ(N, vector<int>(M));
vector<int> fours, ones, eights;
for (int i = 0; i < N; i++)
{
for (int j = 0; j < M; j++)
{
if (occ[i][j])
continue;
int temp = dfs({i, j}, {i, j}, i, j, H, V, occ, N, M, ones, fours, eights);
}
}
sort(ones.begin(), ones.end());
for (int i = 0; i < ones.size() / 2; i++)
swap(ones[i], ones[ones.size() - i - 1]);
sort(fours.begin(), fours.end());
for (int i = 0; i < fours.size() / 2; i++)
swap(fours[i], fours[fours.size() - i - 1]);
sort(eights.begin(), eights.end());
for (int i = 0; i < eights.size() / 2; i++)
swap(eights[i], eights[eights.size() - i - 1]);
vector<vector<vector<vector<int>>>> dp(2, vector<vector<vector<int>>>(ones.size() + 1, vector<vector<int>>(fours.size() + 1, vector<int>(eights.size() + 1, 123456789))));
dp[0][ones.size()][fours.size()][eights.size()] = 0;
dp[1][ones.size()][fours.size()][eights.size()] = 0;
for (int j = ones.size(); j >= 0; j--)
{
for (int k = fours.size(); k >= 0; k--)
{
for (int l = eights.size(); l >= 0; l--)
{
int dp1jk1l = 123456789, dp0jk1l = 123456789, dp1jkl1 = 123456789, dp0jkl1 = 123456789;
if (dp[0][j][k][l] != 123456789)
{
if (j > 0)
{
if (dp[1][j - 1][k][l] == 123456789)
dp[1][j - 1][k][l] = dp[0][j][k][l] - ones[j - 1];
dp[1][j - 1][k][l] = min(dp[1][j - 1][k][l], dp[0][j][k][l] - ones[j - 1]);
}
if (k > 0)
{
if (dp1jk1l == 123456789)
dp1jk1l = dp[0][j][k][l] - fours[k - 1];
dp1jk1l = max(dp1jk1l, dp[0][j][k][l] - fours[k - 1]);
if (dp0jk1l == 123456789)
dp0jk1l = dp[0][j][k][l] + fours[k - 1] + 4;
dp0jk1l = min(dp[0][j][k - 1][l], dp[0][j][k][l] + fours[k - 1] + 4);
}
if (l > 0)
{
if (dp1jkl1 == 123456789)
dp1jkl1 = dp[0][j][k][l] - eights[l - 1];
dp1jkl1 = max(dp1jkl1, dp[0][j][k][l] - eights[l - 1]);
if (dp0jkl1 == 123456789)
dp0jkl1 = dp[0][j][k][l] + eights[l - 1] + 8;
dp0jkl1 = min(dp0jkl1, dp[0][j][k][l] + eights[l - 1] + 8);
}
}
if (dp[1][j][k][l] != 123456789)
{
if (j > 0)
{
if (dp[0][j - 1][k][l] == 123456789)
dp[0][j - 1][k][l] = dp[1][j][k][l] + ones[j - 1];
dp[0][j - 1][k][l] = max(dp[0][j - 1][k][l], dp[1][j][k][l] + ones[j - 1]);
}
if (k > 0)
{
if (dp0jk1l == 123456789)
dp0jk1l = dp[1][j][k][l] + fours[k - 1];
dp0jk1l = min(dp0jk1l, dp[1][j][k][l] + fours[k - 1]);
if (dp1jk1l == 123456789)
dp1jk1l = dp[1][j][k][l] - fours[k - 1] - 4;
dp1jk1l = max(dp1jk1l, dp[1][j][k][l] - fours[k - 1] - 4);
}
if (l > 0)
{
if (dp0jkl1 == 123456789)
dp0jkl1 = dp[1][j][k][l] + eights[l - 1];
dp0jkl1 = min(dp0jkl1, dp[1][j][k][l] + eights[l - 1]);
if (dp1jkl1 == 123456789)
dp1jkl1 = dp[1][j][k][l] - eights[l - 1] - 8;
dp1jkl1 = max(dp1jkl1, dp[1][j][k][l] - eights[l - 1] - 8);
}
}
if (k > 0)
{
if (dp[0][j][k - 1][l] == 123456789)
dp[0][j][k - 1][l] = dp0jk1l;
dp[0][j][k - 1][l] = max(dp[0][j][k - 1][l], dp0jk1l);
if (dp[1][j][k - 1][l] == 123456789)
dp[1][j][k - 1][l] = dp1jk1l;
dp[1][j][k - 1][l] = min(dp[1][j][k - 1][l], dp1jk1l);
}
if (l > 0)
{
if (dp[0][j][k][l - 1] == 123456789)
dp[0][j][k][l - 1] = dp0jkl1;
dp[0][j][k][l - 1] = max(dp[0][j][k][l - 1], dp0jkl1);
if (dp[1][j][k][l - 1] == 123456789)
dp[1][j][k][l - 1] = dp1jkl1;
dp[1][j][k][l - 1] = min(dp[1][j][k][l - 1], dp1jkl1);
}
}
}
}
cout << dp[0][0][0][0];
}
