#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char*mmap();
#define RD(v) int v=0;{int c;while(c=*rp++-48,c>=0)v=v*10+c;}

int a[200001];
int ar[200001];

int en[200001];
int ei[200001];
int eb[400000];

union{
	int uv[400000];
	struct{
		int gn[200001];
		int gb1[200001];
		int gb2[200001];
		int zi[32],zv[32];
	}s;
}u;
#define uv  u.uv
#define gn  u.s.gn
#define gb1 u.s.gb1
#define gb2 u.s.gb2
#define zi  u.s.zi
#define zv  u.s.zv

void f1(int i,int p){
	int b1=0;
	int b2=0;
	for(int k=0;k<en[i];++k){
		int j=eb[ei[i]+k];
		if(j!=p){
			f1(j,i);
			int g=1<<gn[j];
			b2|=b1&g;
			b1|=g;
		}
	}
	gb1[i]=b1;
	gb2[i]=b2;
	gn[i]=__builtin_ctz(~b1);
}

void f2(int i,int p){
	int gi=gn[i];
	int gp=gn[p];
	gp=gb2[p]&1<<gi||gp<gi?gp:gi;
	int bp=1<<gp;
	gb2[i]|=gb1[i]&bp;
	//gb1[i]|=bp;
	gn[i]=gi=__builtin_ctz(~(gb1[i]|bp));
	int g=gi^gp;
	if(ar[i]){
		zi[g]=ar[i];
		zv[g]=p;
	}
	for(int k=0;k<en[i];++k){
		int j=eb[ei[i]+k];
		if(j!=p){
			g=gi^gn[j];
			if(ar[i]){
				zi[g]=ar[i];
				zv[g]=j;
			}
			f2(j,i);
		}
	}
}

main(){
	char*rp=mmap(0l,7*600002,1,2,0,0ll);
	RD(n);
	RD(m);
	for(int l=0;++l<=m;){
		RD(t);
		a[l]=t;
		ar[t]=l;
	}
	{
		int ne=n-1<<1;
		for(int j=0;j<ne;++j){
			RD(t);
			uv[j]=t;
			++en[uv[j]];
		}
	}
	{
		int s=0;
		for(int i=0;++i<=n;){
			ei[i]=s;
			s+=en[i];
			en[i]=0;
		}
	}
	{
		int ne=n-1<<1;
		for(int j=0;j<ne;++j){
			int i=uv[j];
			eb[ei[i]+en[i]++]=uv[j^1];
		}
	}

	gn[0]=31;
	gb2[0]=-1;
	zi[0]=zv[0]=-1;
	f1(1,0);
	f2(1,0);
	int g=0;
	for(int l=0;++l<=m;){
		int i=a[l];
		g^=gn[i];
	}
	printf("%d %d\n",zi[g],zv[g]);
}