#include<bits/stdc++.h>
using namespace std;
const int N=75,P=998244853,i2=P+1>>1;
int n,m,w,a[N][N][1<<12],b[1<<12];
char op[15];
int ksm(int x,int y){
	int res=1;
	for(;y;y>>=1,x=1ll*x*x%P)if(y&1)res=1ll*res*x%P;
	return res;
}
void add(int x,int y,int z){
	--a[x][y][z],++a[y][y][z];
}
inline int md(int x){
	return x>=P?x-P:x;
}
void FWT(int *a){
	for(int i=0;i<w;++i)
		for(int j=0;j<1<<w;j+=1<<i+1)
			for(int k=0;k<1<<i;++k){
				if(op[i]=='&')a[j|k]=md(a[j|k]+a[j|k|1<<i]);
				else if(op[i]=='|')a[j|k|1<<i]=md(a[j|k]+a[j|k|1<<i]);
				else{
					int x=a[j|k],y=a[j|k|1<<i];
					a[j|k]=md(x+y),a[j|k|1<<i]=md(x+P-y);
				}
			}
}
void IFWT(int *a){
	for(int i=0;i<w;++i)
		for(int j=0;j<1<<w;j+=1<<i+1)
			for(int k=0;k<1<<i;++k){
				if(op[i]=='&')a[j|k]=md(a[j|k]+P-a[j|k|1<<i]);
				else if(op[i]=='|')a[j|k|1<<i]=md(a[j|k]+P-a[j|k|1<<i]);
				else{
					int x=a[j|k],y=a[j|k|1<<i];
					a[j|k]=1ll*(x+y)*i2%P,a[j|k|1<<i]=1ll*(x+P-y)*i2%P;
				}
			}
}
int main(){
	scanf("%d%d",&n,&m);
	scanf("%s",op);
	w=strlen(op);
	for(int i=1,x,y,z;i<=n;++i){
		scanf("%d%d%d",&x,&y,&z);
		add(x,y,z),add(y,x,z);
	}
	for(int i=1;i<n;++i)for(int j=1;j<n;++j)FWT(a[i][j]);
	for(int v=0;v<1<<w;++v){
		b[v]=1;
		for(int i=1;i<n;++i){
			if(!a[i][i][v]){
				for(int j=i+1;j<n;++j)if(a[j][i][v]){
					for(int k=i;k<n;++k)swap(a[i][k][v],a[j][k][v]);
					b[v]=P-b[v];
					break;
				}
			}
			if(!a[i][i][v]){
				b[v]=0;
				break;
			}
			b[v]=1ll*b[v]*a[i][i][v]%P;
			int in=ksm(a[i][i][v],P-2);
			for(int j=i+1;j<n;++j){
				int d=1ll*a[j][i][v]*in%P;
				for(int k=i;k<n;++k)a[j][k][v]=(1ll*(P-d)*a[i][k][v]+a[j][k][v])%P;
			}
		}
	}
	IFWT(b);
	for(int i=(1<<w)-1;~i;--i)if(b[i]){
		printf("%d\n",i);
		return 0;
	}
	puts("-1");
	return 0;
}