#include <iostream>

 #include <cstdio>

 #include <cstring>

 using namespace std;

 const int MAXN = ;

 char s[MAXN];

 int n,m;

 int f[MAXN],flag;

 int Find(int x)

 {

     if(x == f[x])

         return x;

     else return f[x] = Find(f[x]);

 }

 void judge(int x,int y)

 {

     if(s[x] == s[y])

         f[x] = y;

     else if(s[x] == '?')

         f[x] = y;

     else if(s[y] == '?')

         f[y] = x;

     else flag = true;

 }

 int main()

 {

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

     int ncase;

     scanf("%d",&ncase);

     while(ncase--) {

         flag = false;

         scanf("%d%d%s",&n,&m,s);

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

             f[i] = i;

         for(int i = ,j = n-;i < j; i++,j--) {

             judge(i,j);

         }

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

             int a,b;

             scanf("%d%d",&a,&b);

             a--,b--;

             judge(Find(a),Find(b));

         }

         if(flag) {

             printf("0\n");

             continue;

         }

         else {

             long long ans = ;

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

                 if(f[i] == i && s[i] == '?') {

                     ans *= ;

                     ans %= ;

                 }

             }

             printf("%lld\n",ans);

         }

     }

     return ;

 }