#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ll long long
#define OO 2'000'000'000
#define ull unsigned long long
#define nl '\n'
#define sz(x) (ll)(x.size())
#define all(x) x.begin(),x.end()
#define rall(s)  s.rbegin(), s.rend()
#define getline(s) getline(cin>>ws,s)
#define ceill(n, m) (((n) / (m)) + ((n) % (m) ? 1 : 0))
#define pi  3.141592653589793
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define multi_ordered_set tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>


void Fast_IO(){
ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
// freopen("filename.in", "r", stdin);
// freopen("filename.txt", "w", stdout);
#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
#endif
}




int dx[] = { 2, 1, -1, -2, -2, -1, 1, 2 };
int dy[] = { 1, 2, 2, 1, -1, -2, -2, -1 };


int n,m,q;

bool good(int sz , vector<vector<int>>&pre){
    for(int i=1;i+sz-1<=n;i++){
        for(int j=1;j+sz-1<=m;j++){
            int sum =0;
            if(i+sz-1<=n && j+sz-1<=m) sum += pre[i+sz-1][j+sz-1];
            if(i-1>=1) sum -= pre[i-1][j+sz-1];
            if(j-1>=1) sum -= pre[i+sz-1][j-1];
            if(i-1>=1 && j-1>=1) sum += pre[i-1][j-1];
            if(sum == 0) return true;
        }
    }
    return false;
}



void solve(){
cin>>n>>m>>q;
int maxi = max(n,m);
vector<vector<int>>v(maxi+5,vector<int>(maxi+5));

auto fill =[&](int x1,int y1,int x2,int y2){
    v[x2][y2]++,v[x2][y1-1]--;
    v[x1-1][y2]--,v[x1-1][y1-1]++;
};

auto build = [&](){
    for(int i=n;i>=1;i--){
        for(int j=m;j>=1;j--){
            v[i][j] += v[i+1][j]+v[i][j+1]-v[i+1][j+1];
        }
    }
};


while(q--){
    int x,y,k;
    cin>>x>>y>>k;
    int l = max(1,x-k),r = min(n,x+k);
    int u = max(1,y-k),d = min(m,y+k);
    // cout<<l<<" "<<r<<" "<<u<<" "<<d<<nl;
    fill(x,l,x,r);
    fill(u,y,d,y);
}

build();

for(int i=1;i<=n;i++){
    for(int j=1;j<=m;j++){
        v[i][j] = min(v[i][j],1);
    }
}

vector<vector<int>>pre = v;

for(int i=1;i<=n;i++){
    for(int j=1;j<=m;j++){
        pre[i][j] += pre[i-1][j]+pre[i][j-1]-pre[i-1][j-1];
    }
}


int l=1,r=min(n,m),ans=-1;

while(l<=r){
    int mid = l+(r-l)/2;
    if(good(mid,pre)){
        ans = mid;
        l = mid+1;
    }else{
        r = mid-1;
    }
}

for(int i=1;i<=n;i++){
    for(int j=1;j<=m;j++){
        cout<<v[i][j]<<" ";
    }
    cout<<nl;
}

if(ans == -1) cout<<-1<<nl;
else cout<<ans*ans<<nl;





}

int main(){
    Fast_IO();
int t =1;
//cin>>t;
while(t--){
solve();
}
return 0;
}