#include <bits/stdc++.h>
using namespace std;
#define ull unsigned long long
#define ll long long
#define ld long double
#define pb push_back
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pld pair<ld,ld>
#define pdd pair<double,double>
#define mp make_pair
#define AmirMakaM ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
//#define int long long
// solve it
const ull SEED = chrono::steady_clock::now().time_since_epoch().count();
mt19937_64 mrand(SEED);
ull rnd(ull x = ~(0ull)) {return mrand() % x;}
const ll MOD = 998244353;
const ll INF = 1e16+20;
const int inf = 1e9 + 7;
const ll N = 1e5+1;
const ll M = 2e3+1;
const double pi = 2*acos(0.0);
const int dx[] = {1,-1,0,0}, dy[] = {0,0,1,-1};
void solve() {
int n, m;
cin >> n >> m;
char a[n+1][m+1];
for(int i=1; i<=n; i++) {
for(int j=1; j<=m; j++) {
cin >> a[i][j];
}
}
set<char> cur;
for(int i=1; i<=n; i++) {
for(int j=1; j<=m; j++) {
cur.insert(a[i][j]);
}
}
if(sz(cur) == 3) cout << 2;
else cout << 1;
}
int main() {
AmirMakaM;
srand(SEED);
//freopen("bulk.in", "r", stdin);
//freopen("bulk.out", "w", stdout);
int ttt = 1;
//cin >> ttt;
while(ttt--) {
solve();
}
}
