/*翻译好题意 n个变量 不超过m*2句话*/

#include<iostream>

#include<cstdio>

#include<cstring>

#include<vector>

#define maxn 200010

using namespace std;

int n,m,f[maxn],c,s[maxn],age[maxn],sum,a,b;

vector<int>G[maxn];

bool Judge(int a,int b)

{

    if(age[a]*n<sum&&age[b]*n<sum)return ;

    if(age[a]*n>=sum&&age[b]*n>=sum)return ;

    return ;

}

void Add(int x,int a,int y,int b)

{

    x=x*+a;y=y*+b;

    G[x^].push_back(y);

    G[y^].push_back(x);

}

bool Dfs(int x)

{

    if(f[x^])return ;if(f[x])return ;

    f[x]=;s[c++]=x;

    for(int i=;i<G[x].size();i++)

      if(!Dfs(G[x][i]))return ;

    return ;

}

bool Solve()

{

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

      {

          if(f[i]||f[i+])continue;c=;

          if(!Dfs(i))

            {

                while(c>)f[s[--c]]=;

                if(!Dfs(i+))return ;

          }

      }

    return ;

}

int main()

{

    while()

      {

          memset(f,,sizeof(f));sum=;

          for(int i=;i<n*;i++)G[i].clear();

          scanf("%d%d",&n,&m);if(n==&&m==)break;

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

            scanf("%d",&age[i]),sum+=age[i];

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

            {

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

                if(a==b)continue;Add(a,,b,);

                if(Judge(a,b))Add(a,,b,);

          }

        if(Solve()==)printf("No solution\n");

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

          {

              if(f[i*])printf("C\n");

              else if(age[i]*n<sum)printf("B\n");

              else printf("A\n");

          }

      }

    return ;

}