using namespace std;
int n,k,v,x[10000005];
int erfen(int n,int k){
    int l=1,r=n,s=-1;
    while(l<=r){
        int mid=(l+r)/2;
        if(x[mid]==k){
            r=mid-1;s=mid;
        }else if(x[mid]<k){
            l=mid+1;
        }else{
            r=mid-1;
        }
    }
    return s;
}
int main(){
    scanf("%d",&n);

    int y;scanf("%d",&y);
    for(int i=1;i<=n;i++)scanf("%d",&x[i]);
    if(erfen(n,y)!=-1)printf("YES\n");
    else printf("NO\n");
    return 0;
}