#include using namespace std; #define repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++) #define rep(i,n) repl(i,0,n) #define mp(a,b) make_pair((a),(b)) #define pb(a) push_back((a)) #define all(x) (x).begin(),(x).end() #define uniq(x) sort(all(x)),(x).erase(unique(all(x)),end(x)) #define fi first #define se second #define dbg(x) cout<<#x" = "<<((x))< ostream& operator<<(ostream& o, const pair &p){o<<"("< ostream& operator<<(ostream& o, const vector &v){o<<"[";for(T t:v){o< par, rank; // parent(negative := its root and abs-value is its size), depth UnionFind(int sz) : par(sz, -1), rank(sz, 0){} int find(int x){ if(par[x]<0) return x; else return par[x] = find(par[x]); } void unite(int x, int y){ x=find(x); y=find(y); if(x==y) return; // already belong to same tree if(rank[x] < rank[y]){ // y becomes parent node par[y] += par[x]; par[x] = y; } else { // x becomes parent node par[x] += par[y]; par[y] = x; if(rank[x]==rank[y]) rank[x]++; } } bool same(int x, int y){ return find(x) == find(y); } int size(int x){ return -par[find(x)]; } }; // END class UnionFind int main(){ int n; long k; cin>>n>>k; UnionFind uf(n); rep(i,n){ int d; cin>>d; if(i+1!=d){ uf.unite(i, d-1); } } int req = 0; rep(i,n) if(uf.par[i]<0){ req += -uf.par[i] - 1; } k -= req; if(k>=0 && k%2==0) cout<<"YES"<