#include<bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define ins insert
#define pq priority_queue
#define minele min_element
#define maxele max_element
#define mp make_pair
#define lb lower_bound //first pos >= val
#define ub upper_bound // first pos > val
#define cnt_bit __builtin_popcount
#define all(x) x.begin(), x.end()
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,fma")
using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;

int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};

int dx[8] = {-2, -1, 1, 2, 2, 1, -1, -2};
int dy[8] = {1, 2, 2, 1, -1, -2, -2, -1};

const int INF = 1e9;
const ll oo = 1e18;
const ll maxN = 1e6;

/* Author : Le Ngoc Bao Anh, 11A5, LQD High School for Gifted Student */

struct Dinitz {
    struct Edges {
        int u, v;
        ll cap;

        Edges() : u(), v(), cap() {}
        Edges(int _u, int _v, ll _cap) : u(_u), v(_v), cap(_cap) {}
    };

    vector<vector<int>> g;
    vector<Edges> ed;
    vector<int> dist;
    vector<int> id;
    int S, T;
    int n;

    Dinitz() : ed(), n(), S(), T() {}
    Dinitz(int _n, int _S, int _T) {
        n = _n; S = _S; T = _T;
        g.resize(n);
        dist.resize(n);
        id.resize(n);
        for(int i = 0; i < n; i++) g[i].clear();
        ed = vector<Edges>();
    }

    void addEdge(int u, int v, ll cap) {
        g[u].pb((int)ed.size());
        ed.pb(Edges(u, v, cap));
        g[v].pb((int)ed.size());
        ed.pb(Edges(v, u, 0));
    }

    bool bfs() {
        for(int i = 0; i < n; i++) dist[i] = n + 5;
        queue<int> q;
        q.push(S); dist[S] = 0;
        while(!q.empty()) {
            int u = q.front(); q.pop();
            for(int i : g[u]) {
                Edges e = ed[i];
                if(!e.cap) continue;
                if(dist[e.v] <= dist[u] + 1) continue;
                dist[e.v] = dist[u] + 1;
                q.push(e.v);
            }
        }

        return dist[T] < n + 5;
    }

    ll dfs(int u, ll flow) {
        if(u == T || flow == 0) return flow;

        ll ans = 0;
        for(int &i = id[u]; i < (int)g[u].size(); i++) {
            Edges e = ed[g[u][i]];
            if(!e.cap) continue;
            if(dist[e.v] != dist[u] + 1) continue;
            ll f = dfs(e.v, min(flow, e.cap));
            flow -= f;
            ans += f;
            ed[g[u][i]].cap -= f;
            ed[g[u][i] ^ 1].cap += f;
            if(flow == 0) return ans;
        }

        return ans;
    }

    ll Flow() {
        ll ans = 0;
        while(bfs()) {
            for(int i = 0; i < n; i++) id[i] = 0;
            ans += dfs(S, oo);
        }

        return ans;
    }

    vector<pii> getEdge() {
        vector<pii> ans;
        for(int i = 0; i < ed.size(); i++) {
            int u = ed[i].u, v = ed[i].v;
            if(u == S || v == S || u == T || v == T) continue;
            if(!(u & 1)) continue;
            if(!ed[i].cap) ans.pb(make_pair(u, v));
        }

        return ans;
    }
};

struct TWOSAT {
    int n;
    vector<vector<int>> g;
    vector<vector<int>> ed;
    vector<int> Num;
    vector<int> Low;
    vector<int> idComp;
    vector<bool> visited;
    stack<int> st;
    vector<int> ord;
    vector<int> idSort;
    int Time, cntComp;

    TWOSAT(int _n = 0) {
        n = _n;
        g.resize(2 * n + 2);
        ed.resize(2 * n + 2);
        Num.resize(2 * n + 2);
        Low.resize(2 * n + 2);
        visited.resize(2 * n + 2);
        idComp.resize(2 * n + 2);
        idSort.resize(2 * n + 2);
        ord.clear();
        Time = cntComp = 0;

        for(int i = 1; i <= 2 * n; i++) {
            g[i].clear(); ed[i].clear();
            idSort[i] = Num[i] = visited[i] = Low[i] = idComp[i] = 0;
        }
    }

    int NOT(int u) {
        return (u > n ? u - n : u + n);
    }

    void Connect(int u, int v) {
        g[u].pb(v);
    }

    void addEdge(int u, int v) {
        // u || v = 1
        Connect(NOT(u), v);
        Connect(NOT(v), u);
    }

    void tarjan(int u) {
        Num[u] = Low[u] = ++Time;
        st.push(u);

        for(auto v : g[u]) {
            if(Num[v]) {
                Low[u] = min(Low[u], Num[v]);
            } else {
                tarjan(v);
                Low[u] = min(Low[u], Low[v]);
            }
        }

        if(Num[u] == Low[u]) {
            int v = 0;
            ++cntComp;
            do {
                v = st.top(); st.pop();
                idComp[v] = cntComp;
                Num[v] = Low[v] = INF;
            } while(v != u);
        }
    }

    void topo(int u) {
        visited[u] = true;
        for(auto v : ed[u]) {
            if(!visited[v]) topo(v);
        }

        ord.pb(u);
    }

    vector<int> do2SAT() {
        for(int i = 1; i <= 2 * n; i++) {
            if(!Num[i]) tarjan(i);
        }

        for(int i = 1; i <= n; i++) {
            if(idComp[i] == idComp[i + n]) return {-1};
        }

        vector<int> ans;
        for(int i = 1; i <= 2 * n; i++) {
            int u = idComp[i];
            for(auto v : g[i]) {
                v = idComp[v];
                if(u == v) continue;
                ed[u].pb(v);
            }
        }

        for(int i = 1; i <= 2 * n; i++) {
            if(!visited[i]) topo(i);
        }
        reverse(all(ord));

        for(int i = 0; i < 2 * n; i++) idSort[ord[i]] = i + 1;

        for(int i = 1; i <= n; i++) {
            int u = idComp[i], v = idComp[i + n];
            if(idSort[u] > idSort[v]) ans.pb(i);
        }

        return ans;
    }
};

const int N = 105;
bool banned[N][N];
bool ok[N * N];

void solve() {
    int n, m, k; cin >> n >> m >> k;
    for(int i = 1; i <= k; i++) {
        int x, y; cin >> x >> y;
        banned[x][y] = true;
    }

    auto node = [&](int i, int j) -> int {
        return (i - 1) * m + j;
    };

    auto inside = [&](int i, int j) -> bool {
        return (i > 0 && j > 0 && i <= n && j <= m && !banned[i][j]);
    };

    Dinitz G = Dinitz(n * m + 5, 0, n * m + 1);
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            if(banned[i][j]) continue;
            if(node(i, j) & 1) G.addEdge(0, node(i, j), 1);
            else G.addEdge(node(i, j), n * m + 1, 1);
        }
    }

    TWOSAT S = TWOSAT(n * m);
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            if(!(node(i, j) & 1) || banned[i][j]) continue;
            for(int r = 0; r < 8; r++) {
                int x = i + dx[r], y = j + dy[r];
                if(!inside(x, y)) continue;
                G.addEdge(node(i, j), node(x, y), 1);
                S.addEdge(node(i, j), node(x, y));
            }
        }
    }

    int flow = G.Flow();
    vector<pii> mf = G.getEdge();

    int numNodes = n * m;
    for(int i = 0; i < mf.size(); i++) {
        int u = mf[i].fi, v = mf[i].se;
        ok[u] = ok[v] = true;
        S.addEdge(u + numNodes, v + numNodes);
    }

    for(int i = 1; i <= n * m; i++) {
        if(!ok[i]) S.addEdge(i + numNodes, i + numNodes);
    }

    vector<int> notChosen = S.do2SAT();

    for(int i = 0; i < notChosen.size(); i++) {
        int id = notChosen[i];
        int u = (id - 1) / m + 1, v = (id - 1) % m + 1;
        banned[u][v] = true;
    }

    vector<pii> ans;
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            if(!banned[i][j]) ans.pb(make_pair(i, j));
        }
    }

    cout << ans.size() << '\n';
    for(int i = 0; i < ans.size(); i++) {
        cout << ans[i].fi << " " << ans[i].se << '\n';
    }
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #else
    //online
    #endif

    int tc = 1, ddd = 0;
    // cin >> tc;
    while(tc--) {
        //ddd++;
        //cout << "Case #" << ddd << ": ";
        solve();
    }
}