#include<bits/stdc++.h>
using namespace std;
int a, b, m;
vector<int>t[100005];
int have[100005];
int to[100005];
signed main(){
    // freopen("ex_data3.in", "r", stdin);
    cin >> a >> b >> m;
    for(int i = 1; i <= m; i++){
        int x, y;
        scanf("%d%d", &x, &y);
        if(x == a)to[y] ^= 1;
        else t[x].push_back(y);
    }
    for(int i = 1; i < a; i++){
        int len = t[i].size();
        for(int j = 0; j < len; j++){
            // to[t[i][j]] ^= 1;
            // to[t[i][j + 1]] ^= 1;
            have[i] ^= 1;
            to[t[i][j]] ^= 1;
            to[b] ^= 1;
        }
    }
    int ans = 0;
    int s1 = 0, s2 = 0;
    for(int i = 1; i < a; i++)s1 += have[i];
    for(int i = 1; i <= b; i++)s2 += to[i];
    // for(int i = 1; i < a; i++)cout << have[i] << " ";
    // cout << endl;
    // for(int i = 1; i <= b; i++)cout << to[i] << " ";
    // cout << endl;
    ans = s1 + s2;
    if(to[b]){
        s2--;
        int v = min(s1/2, s2/2);
        ans -= v * 2;
        s1 -= v*2;
        s2 -= v*2;
        if(s1 && s2){
            ans -= 2;
        }
    }else{
        int v = min(s1/2, s2/2);
        ans -= v * 2;
    }
    cout << ans << endl;
    return 0;
}