#include #define rep(i,n) for (int i = 0; i < (n); ++i) #define rrep(i,n) for (int i = (n)-1; i >= 0; i--) #define rep2(i,s,n) for (int i = (s); i < (n); ++i) #define all(a) a.begin(),a.end() #define rall(a) a.rbegin(),a.rend() #define pb push_back #define eb emplace_back #define vi vector #define vvi vector> #define vl vector #define vvl vector> #define vd vector #define vs vector #define vc vector #define vb vector #define vp vector

using namespace std; using ll = long long; using P = pair; using LP = pair; template istream& operator>>(istream& is,vector& v) { for(T& t:v){is>>t;} return is; } template ostream& operator<<(ostream& os,const vector& v) { rep(i,v.size())os< inline bool chmin(T& a,T b) {if(a > b){a = b; return true;} return false;} template inline bool chmax(T& a,T b) {if(a < b){a = b; return true;} return false;} const int inf = 1001001001; const ll linf = 1001001001001001001; // Decomposition of Strongly Connected Components class scc { int n; vvi G,rG; vi ord,bel; vb used; void init() { rG.resize(n); rep(i,n) for(int j : G[i]) rG[j].pb(i); bel.resize(n); used.resize(n); } void dfs(int v) { used[v] = true; for(int u : G[v]) if(!used[u]) dfs(u); ord.pb(v); } void rdfs(int v,int k) { used[v] = true; bel[v] = k; for(int u : rG[v]) if(!used[u]) rdfs(u,k); } public: // number of components int num; scc(vvi G):G(G) { n = G.size(); init(); used.assign(n,false); rep(i,n) if(!used[i]) dfs(i); used.assign(n, false); int k = 0; rrep(i,n) if(!used[ord[i]]) rdfs(ord[i],k++); num = k; } // belonging components(topological order) int get(int i) { return bel[i]; } }; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); int n,m; cin >> n >> m; vi l(n),r(n); rep(i,n) cin >> l[i] >> r[i]; vvi G(2*n); rep(i,n) rep(j,i) { // i => !j , j => !i // !i => j , !j => i if(l[i] <= r[j] && l[j] <= r[i]) { G[i].pb(n+j); G[j].pb(n+i); G[n+i].pb(j); G[n+j].pb(i); } // !i => !j , j => i if(m-1-r[i] <= r[j] && l[j] <= m-1-l[i]) { G[n+i].pb(n+j); G[j].pb(i); } // i => j , !j => !i if(l[i] <= m-1-l[j] && m-1-r[j] <= r[i]) { G[i].pb(j); G[n+j].pb(n+i); } } scc sc(G); rep(i,n) if(sc.get(i) == sc.get(n+i)) { YES(0); return 0; } YES(1); }