#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
using namespace std;
inline int read()
{
	char c=getchar();int x=0;bool f=0;
	for(;!isdigit(c);c=getchar())f^=!(c^45);
	for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
	if(f)x=-x;return x;
}

#define mod 998244353
struct modint{
	int x;
	modint(int o=0){x=o;}
	modint &operator = (int o){return x=o,*this;}
	modint &operator +=(modint o){return x=x+o.x>=mod?x+o.x-mod:x+o.x,*this;}
	modint &operator -=(modint o){return x=x-o.x<0?x-o.x+mod:x-o.x,*this;}
	modint &operator *=(modint o){return x=1ll*x*o.x%mod,*this;}
	modint &operator ^=(int b){
		modint a=*this,c=1;
		for(;b;b>>=1,a*=a)if(b&1)c*=a;
		return x=c.x,*this;
	}
	modint &operator /=(modint o){return *this *=o^=mod-2;}
	friend modint operator +(modint a,modint b){return a+=b;}
	friend modint operator -(modint a,modint b){return a-=b;}
	friend modint operator *(modint a,modint b){return a*=b;}
	friend modint operator /(modint a,modint b){return a/=b;}
	friend modint operator ^(modint a,int b){return a^=b;}
	friend bool operator ==(modint a,int b){return a.x==b;}
	friend bool operator !=(modint a,int b){return a.x!=b;}
	bool operator ! () {return !x;}
	modint operator - () {return x?mod-x:0;}
	bool operator <(const modint&b)const{return x<b.x;}
};
inline modint qpow(modint x,int y){return x^y;}

vector<modint> fac,ifac,iv;
inline void initC(int n)
{
	if(iv.empty())fac=ifac=iv=vector<modint>(2,1);
	int m=iv.size(); ++n;
	if(m>=n)return;
	iv.resize(n),fac.resize(n),ifac.resize(n);
	For(i,m,n-1){
		iv[i]=iv[mod%i]*(mod-mod/i);
		fac[i]=fac[i-1]*i,ifac[i]=ifac[i-1]*iv[i];
	}
}
inline modint C(int n,int m){
	if(m<0||n<m)return 0;
	return initC(n),fac[n]*ifac[m]*ifac[n-m];
}
inline modint sign(int n){return (n&1)?(mod-1):(1);}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 2000005
#define inf 0x3f3f3f3f

#define bint bitset<2005>
int n,m;
vector<vi>res;
bint a[2005],tmp;
bitset<4005>e[4005];

int cnt;
void dfs(bitset<4005>S,int u){
	if((S&(S<<m)).count())return;
//	cout<<"u: "<<u<<endl;
//	For(i,1,m*2)cout<<S[i];puts(""); 
	if(u==m+1){
		++cnt;
		if(cnt>n)puts("-1"),exit(0);
		return;
	}
	if(!S[u]) dfs(S|e[u+m],u+1);
	if(!S[u+m]) dfs(S|e[u],u+1);
}

int rd(){
	char ch;
	while(!isdigit(ch=getchar()));
	return ch&1;
}

signed main()
{
	n=read(),m=read();
	For(i,1,n)
		For(j,1,m)a[j][i]=rd();
	For(i,1,m*2)e[i][i]=1;
	For(u,1,m)
		For(v,u,m){
			For(i,0,1)
				For(j,0,1){
					if(u==v && i!=j) continue;
					tmp=(!i?a[u]:(~a[u]))&(!j?a[v]:(~a[v]));
					
			//		cout<<"i,j "<<u<<" "<<v<<" "<<i<<" "<<j<<endl;
			//		For(_,1,n)cout<<tmp[_];puts("");
					if(tmp._Find_next(0)<=n) continue;
			//		puts("QAQ");
					res.pb({u-1,v-1,i+1+j*2});
					e[u+m*(!i)][v+m*j]=1;
					e[v+m*(!j)][u+m*i]=1;
				}
		}
//	For(i,1,m*2)For(j,1,m*2){
//		cout<<e[i][j];
//		if(j==m*2)puts("");
//	}
	bitset<4005>tmp;
	tmp.reset();
	dfs(tmp,1);
//	cout<<"cnt "<<cnt<<endl;
	if(cnt!=n)puts("-1"),exit(0); 
	cout<<res.size()<<"\n";
	for(auto it:res){
		for(int x:it)cout<<x<<" ";
		cout<<"\n";
	}
	return 0;
}