## Editorial for Bedao Mini Contest 03 - TILE

Remember to use this editorial only when stuck, and not to copy-paste code from it. Please be respectful to the problem author and editorialist.
Submitting an official solution before solving the problem yourself is a bannable offence.

#### Code mẫu

#include <bits/stdc++.h>
#define io ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define ll long long
#define fi first
#define se second

using namespace std;

int n, m;

int main()
{
freopen("TILE.INP","r",stdin);
freopen("TILE.OUT","w",stdout);
io;
cin >> n >> m;
int r1 = 0, r2 = 0;
for (int i = 1; i <= n; ++i)
for (int j = 1; j <= m; ++j)
{
char v;
cin >> v;
if (((i + j) & 1) == (v - '0')) ++r1; else ++r2;
}
cout << min(r1,r2);
return 0;
}