#include <iostream>
#include <vector>
#include <assert.h>
#include <algorithm>
#include <cstring>
using namespace std;
typedef long long ll;
typedef long double ld;
#define PB push_back
#define MP make_pair
#define MOD 1000000007LL
#define endl "\n"
const ll UNDEF = -1;
const ll INF=1e18;
template<typename T> inline bool chkmax(T &aa, T bb) { return aa < bb ? aa = bb, true : false; }
template<typename T> inline bool chkmin(T &aa, T bb) { return aa > bb ? aa = bb, true : false; }
const ll MAXN=2004;
vector<vector<int> > graph, rev_graph;
int used[2*MAXN], comp[2*MAXN], order[2*MAXN], res[2*MAXN], cnt = 0;
void dfs1(int u) { used[u] = true;
  for (auto i = 0u; i < graph[u].size(); i++) {
    int v = graph[u][i];
    if (!used[v]) dfs1(v); }
  order[cnt++] = u; }
void dfs2(int u, int color) { comp[u] = color;
  for (auto i = 0u; i < rev_graph[u].size(); i++) {
    int v = rev_graph[u][i];
    if (comp[v] == -1) dfs2(v, color); } }
bool twosat() { int n = graph.size();
  for (int i = 0; i < n; i++) if (!used[i]) dfs1(i);
  for (int i = 0; i < n; i++) for (auto j = 0u; j < graph[i].size(); j++)
    rev_graph[graph[i][j]].push_back(i);
  for (int i = 0, color = 0; i < n; i++) {
    int u = order[n-i-1];
    if (comp[u] == -1) dfs2(u, color++); }
  for (int i = 0; i < n; i++) if (comp[i] == comp[i^1]) return false;
  for (int i = 0; i < n; i+=2) res[i/2] = (comp[i] > comp[i^1]);
  return true; }
void init_twosat(ll vars) {
  ll n=2*vars;
  graph.clear(); rev_graph.clear();
  graph.resize(2*n);
  rev_graph.resize(2*n);
  memset(order, 0, sizeof order);
  memset(comp, -1, sizeof comp);
  memset(used, 0,  sizeof used);
  cnt=0;
}
//if type = 0, we add the edge x -> y, if type = 1, we add the edge ~x -> y
//if type = 2, we add the edge x -> ~y, if type = 3, we add the edge ~x -> ~y
//NOTE: each implication and its dual implication is also added, so NO need to
//add twice for each implication.
void add(int x, int y) { graph[x].push_back(y); };
void add_edge(int x, int y, int type) { int a=2*x, na=2*x+1, b=2*y, nb=2*y+1;
	//printf("ae: %d %d %d",x,y,type);
  switch (type) {
    case 0: add(a,b); add(nb, na); break;
    case 1: add(na, b); add(nb, a); break;
    case 2: add(a, nb); add(b, na); break;
    case 3: add(na, nb); add(b,a); break; } }
const ll mn=1004;
ll px[mn],py[mn];
int main() {
  ll _n,r,l; scanf("%lld%lld%lld",&_n,&r,&l);
  for (ll i=0;i<l;i++){
    scanf("%lld%lld",&px[i],&py[i]);
  }
  init_twosat(l);
  for (ll a=0;a<l;a++) {
    ll ax=px[a],ay=py[a];
    for (ll b=0;b<l;b++) {
      if (a==b) continue;
      ll bx=px[b],by=py[b];
      if (ay==by&&abs(ax-bx)<=(2*r-2)) {
        //printf("%lld %lld hor implies %lld %lld vert\n",ax,ay,bx,by);
        add_edge(a,b,2);
      }
      if (ax==bx&&abs(ay-by)<=(2*r-2)) {
        //printf("%lld %lld vert implies %lld %lld hor\n",ax,ay,bx,by);
        add_edge(a,b,1);
      }
    }
  }
  bool possible=twosat();
  if (possible) printf("YES\n");
  else printf("NO\n");
}