//minamoto

 #include<iostream>

 #include<cstdio>

 #include<cstring>

 #define mem(a) (memset(a,0,sizeof(a)))

 #define swap(x,y) (x^=y^=x^=y)

 #define neg(x) (x>n?x-n:x+n)

 using namespace std;

 template<class T>inline bool cmin(T&a,const T&b){return a>b?a=b,:;}

 inline int read(){

     #define num ch-'0'

     char ch;bool flag=;int res;

     while(!isdigit(ch=getchar()))

     (ch=='-')&&(flag=true);

     for(res=num;isdigit(ch=getchar());res=res*+num);

     (flag)&&(res=-res);

     #undef num

     return res;

 }

 inline char getc(){

     char ch;while((ch=getchar())!='A'&&ch!='B'&&ch!='C');return ch;

 }

 const int N=2e5+;

 int head[N],Next[N],ver[N],tot;

 inline void add(int u,int v){

     ver[++tot]=v,Next[tot]=head[u],head[u]=tot;

 }

 int dfn[N],low[N],bl[N],st[N],num,cnt,top,n,m,d;

 void tarjan(int u){

     dfn[u]=low[u]=++num,st[++top]=u;

     for(int i=head[u];i;i=Next[i]){

         int v=ver[i];

         if(!dfn[v]) tarjan(v),cmin(low[u],low[v]);

         else if(!bl[v]) cmin(low[u],dfn[v]);

     }

     if(dfn[u]==low[u]) for(++cnt;st[top+]!=u;--top) bl[st[top]]=cnt;

 }

 inline void clear(){

     mem(head),mem(dfn),mem(bl),mem(st);

     tot=num=cnt=;

 }

 int a1[N],b1[N],Sooke[N];char s[N],a2[N],b2[N],QAQ[N];

 int flag=;

 int tran(int x,char ch){

     if(s[x]=='a') return ch=='B'?x:x+n;

     if(s[x]=='b'||s[x]=='c') return ch=='A'?x:x+n;

     if(ch=='C') return x+n;return x;

 }

 bool solve(){

     clear();

     for(int i=;i<=m;++i)

     if(s[a1[i]]!='x'&&s[b1[i]]!='x'){

         if(a2[i]==s[a1[i]]-) continue;

         int u=tran(a1[i],a2[i]),v;

         if(b2[i]==s[b1[i]]-){add(u,neg(u));continue;}

         v=tran(b1[i],b2[i]),add(u,v),add(neg(v),neg(u));

     }else{

         char o=s[a1[i]],p=s[b1[i]];

         int u,v,x=Sooke[a1[i]],y=Sooke[b1[i]];

         if(o=='x'&&p=='x'){

             if(a2[i]==QAQ[x]) continue;

             u=tran(a1[i],a2[i]);

             if(b2[i]==QAQ[y]){add(u,neg(u));continue;}

             v=tran(b1[i],b2[i]),add(u,v),add(neg(v),neg(u));

         }else if(o=='x'&&p!='x'){

             if(a2[i]==QAQ[x]) continue;

             u=tran(a1[i],a2[i]);

             if(b2[i]==s[b1[i]]-){add(u,neg(u));continue;}

             v=tran(b1[i],b2[i]),add(u,v),add(neg(v),neg(u));

         }else{

             if(a2[i]==s[a1[i]]-) continue;

             u=tran(a1[i],a2[i]);

             if(b2[i]==QAQ[y]){add(u,neg(u));continue;}

             v=tran(b1[i],b2[i]),add(u,v),add(neg(v),neg(u));

         }

     }

     for(int i=,l=n<<;i<=l;++i) if(!dfn[i]) tarjan(i);

     for(int i=;i<=n;++i) if(bl[i]==bl[i+n]) return ;

     for(int i=;i<=n;++i)

     if(bl[i]<bl[i+n]){

         if(s[i]=='a') putchar('B');

         else if(s[i]=='b'||s[i]=='c') putchar('A');

         else if(QAQ[Sooke[i]]=='A') putchar('B');

         else putchar('A');

     }else{

         if(s[i]=='a'||s[i]=='b') putchar('C');

         else if(s[i]=='c') putchar('B');

         else if(QAQ[Sooke[i]]=='A') putchar('C');

         else putchar('B');

     }

     return ;

 }

 void dfs(int dep){

     if(dep>d){

         if(!flag) flag=solve();

         if(flag) exit();

         return;

     }

     QAQ[dep]='A',dfs(dep+);

     QAQ[dep]='B',dfs(dep+);

 }

 int main(){

 //    freopen("testdata.in","r",stdin);

     n=read(),read();

     scanf("%s",s+),m=read();

     for(int i=;i<=n;++i) if(s[i]=='x') Sooke[i]=++d;

     for(int i=;i<=m;++i)

     a1[i]=read(),a2[i]=getc(),b1[i]=read(),b2[i]=getc();

     dfs();

     if(!flag) printf("%d",-);

     return ;

 }