#include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> #define ll long long #define ld long double #define ull unsigned long long #define ff first #define ss second #define pii pair<int,int> #define pll pair<long long, long long> #define vi vector<int> #define vl vector<long long> #define pb push_back #define rep(i, b) for(int i = 0; i < (b); ++i) #define rep2(i,a,b) for(int i = a; i <= (b); ++i) #define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c) #define count_bits(x) __builtin_popcountll((x)) #define all(x) (x).begin(),(x).end() #define siz(x) (int)(x).size() #define forall(it,x) for(auto& it:(x)) using namespace __gnu_pbds; using namespace std; typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set; //mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());} //ll los(ll a, ll b) {return a + (mt() % (b-a+1));} const int INF = 1e9+50; const ll INF_L = 1e18+40; const ll MOD = 1e9+7; const int maxn = (1<<13)*13*2; int n; struct state { int mask,pref; bool was; int to_int() { return mask+(int)was*(1<<n)+(int)pref*(1<<n)*2; } vi get_nxt() { vi ans; if(mask&(1<<(pref))) { state nxt = {mask-(1<<pref),(pref+1)%n,0}; ans = {nxt.to_int()}; } else { if(!was && pref != 0) { state nxt = {mask+(1<<pref)+(1<<(pref-1)),(pref+1)%n,(pref != n-1)}; ans.pb(nxt.to_int()); } if((mask&(1<<(pref+1))) == 0 && pref != n-1) { state nxt = {mask+(1<<pref)+(1<<(pref+1)),pref+1,1}; ans.pb(nxt.to_int()); } if((mask&(1<<(pref+1))) == 0 && pref != n-1) { state nxt = {mask+(1<<(pref+1)),(pref+2)%n,(pref != n-2)}; ans.pb(nxt.to_int()); } if(pref < n-2 && (mask & (1<<(pref+1))) == 0 && (mask & (1<<(pref+2))) == 0) { state nxt = {mask+(1<<pref)+(1<<(pref+1))+(1<<(pref+2)),(pref+3)%n,(pref != n-3)}; ans.pb(nxt.to_int()); } if(pref < n-1 && (mask & (1<<(pref+1))) != 0) { state nxt = {mask+(1<<pref),(pref+2)%n,(pref != n-2)}; ans.pb(nxt.to_int()); } } return ans; } }; vi graph[maxn]; int dist[maxn]; void gen_nxt_layer(vi& cur, vi& ans) { rep(i,(1<<n)*n*2) dist[i] = INF; forall(it,cur) dist[it] = 0; rep(i,(1<<n)*n*2) if(dist[i] != INF && (i >= (1<<n) || dist[i] == 0)) forall(it,graph[i]) dist[it] = 1; ans = {}; rep(i,(1<<n)) if(dist[i] == 1) ans.pb(i); } int main() { ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); //random_start(); int h,k; cin >> n >> h >> k; int period_start = 40; int period = 6; if(h <= 1000) period_start = 1000; rep(i,n) { rep(mask,(1<<n)) { rep(was,2) { state cur = {mask,i,(bool)was}; graph[cur.to_int()] = cur.get_nxt(); } } } map<int,int> H_mask; set<int> stops; rep(i,k) { int y,x; cin >> x >> y; x--; H_mask[y] += (1<<x); stops.insert(y); } vi cur = {0}; int cur_jumps = 0; vi cur2; rep2(i,1,h) { cur2 = {}; forall(it,cur) if((it & H_mask[i]) == 0) cur2.pb(it+H_mask[i]); auto it = stops.upper_bound(i); int nxt_stop = h; if(it != stops.end()) nxt_stop = *it; if(cur_jumps < period_start || i%period != nxt_stop%period) { if(i != h) gen_nxt_layer(cur2,cur); else cur = cur2; if(H_mask[i] == 0) cur_jumps++; else cur_jumps = 0; } else { i = nxt_stop-1; cur_jumps = 0; } } bool is = 0; forall(it,cur) if(it == (1<<n)-1) is = 1; if(is) cout << "YES\n"; else cout << "NO\n"; }