#include<bits/stdc++.h>
using namespace std;
#define int long long
//use ll instead of int.
#define f(i, a, b) for(int i = (a); i <= (b); i++)
#define cl(i, n) i.clear(),i.resize(n);
#define endl '\n'
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int inf = 1e9;
//#define cerr if(false)cerr
//#define freopen if(false)freopen
#define watch(x) cerr  << (#x) << ' '<<'i'<<'s'<<' ' << x << endl
void pofe(int number, int bitnum) {
    string s; f(i, 0, bitnum) {s += char(number & 1) + '0'; number >>= 1; } 
    reverse(s.begin(), s.end()); cerr << s << endl; 
    return;
}
template <typename TYP> void cmax(TYP &x, TYP y) {if(x < y) x = y;}
template <typename TYP> void cmin(TYP &x, TYP y) {if(x > y) x = y;}
//调不出来给我对拍！
//use std::array.
time_t alltime = 0;
int ord[2020];bool vt[4000000][4];bool s[2020][2020];
int n,m; struct syz {int x,y,z;};bitset<2000> bs[2020][2];
int trie[2020*2020][2];int cnt=1;bitset<2000> memo;bitset<2000> cs[2020][2][2]; //
int yg[2020][2];bool fb[2020][2];
bool dfs(int step, int cur) {
    // time_t start = clock();
  //  cerr<<step<<" "<<cur<<endl;
  //  f(i,0,step-1)cerr<<memo[i];
  //  cerr<<endl;
    if(step==m){return cur;}
    f(i,0,1){
        if(fb[step][i]) continue;
        memo[step]=i;
      //  bool ok=1;
         int same=0;
        bitset<2000> th = cs[step][i][0] ^ memo;
        same+=2000-th.count();
        th = cs[step][i][1] ^ memo;
        same+=2000-th.count();
        //cerr<<step<<" "<<i<<" "<<same<<endl;
      //  f(j,0,step-1)if(vt[j*m+step][(memo[j]<<1) + i]==0){ok=0;break;}
       // if(vt[step*m+step][(i<<1)+i]==0){ok=0;}
        if(same==yg[step][i] + 2000){
            
            if(cur==0){
                if(!dfs(step+1,0)) return 0;
                
            }
            else {
                if(!dfs(step+1,trie[cur][i])) return 0;
            }
        }
        memo[step]=0;
    }
    // time_t finish = clock(); alltime += finish - start ;
    return 1;
}
void build(){
    f(i,0,n-1){
        int cur=1;
        f(j,0,m-1){
            if(!trie[cur][s[i][j]]) trie[cur][s[i][j]] = ++cnt;
            cur = trie[cur][s[i][j]];
        }
    }
    return;
}
signed main() {
    ios::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    //  freopen("G.in","r",stdin);
    //  freopen("G.out","w",stdout);
    //freopen();
    
    //think twice,code once.
    //think once,debug forever.
    cin>>n>>m;
    f(i,0,n-1){f(j,0,m-1){char ct;cin>>ct;bs[j][s[i][j]=ct-'0'][i]=1;}}build();
    mt19937 rng(time(0));
    shuffle(ord+1,ord+n+1,rng);vector<syz> v;
    f(t,0,3)f(i,0,m-1)f(j,i,m-1){
        bitset<2000> x = bs[i][t>>1] & bs[j][t&1];
        if(!x.any()){if(i!=j || t==0 || t==3)v.push_back({i,j,(t==0?4:(t==3?1:t+1))});}
        else vt[i*m+j][t] = 1; 
    }
    f(j,0,m-1)f(t,0,1) {
        f(i,0,j) {
            if(vt[i*m+j][t] == 1 && vt[i*m+j][2+t] == 1) {cs[j][t][0][i]=0;cs[j][t][1][i]=1;} //j choose t -> i can choose both
            else if(vt[i*m+j][t] == 0 && vt[i*m+j][2+t] == 0) {fb[j][t]=1;}
            else if(vt[i*m+j][t] == 1) {cs[j][t][0][i]=cs[j][t][1][i]=0;yg[j][t]++;}
            else {cs[j][t][0][i]=cs[j][t][1][i]=1;yg[j][t]++;}
        }
        yg[j][t]+=1999-j;
      //  cerr<<j<<" "<<t<<" "<< yg[j][t] << endl;
    }
    if(!dfs(0,1)) {
        cout << -1 << endl;
        
     //   cerr << "time used:" << alltime * 1.0 / CLOCKS_PER_SEC <<"s"<< endl;
        return 0;
    }
     
     cout<<v.size()<<endl;
     for(syz it : v)cout<<it.x<<" "<<it.y<<" "<<it.z<<endl;
     
    
    // cerr << "time used:" << alltime * 1.0 / CLOCKS_PER_SEC <<"s"<< endl;
    return 0;
}
/*
2023/4/29
start thinking at 11:24


start coding at h:mm
finish debugging at h:mm
*/