#include <iostream>

 #include <cstdio>

 #include <cstring>

 #include <cstdlib>

 #include <algorithm>

 #include <queue>

 #include <vector>

 #include <map>

 #include <string>

 #include <cmath>

 #define min(a, b) ((a) < (b) ? (a) : (b))

 #define max(a, b) ((a) > (b) ? (a) : (b))

 #define abs(a) ((a) < 0 ? (-1 * (a)) : (a))

 template<class T>

 inline void swap(T &a, T &b)

 {

     T tmp = a;a = b;b = tmp;

 }

 inline void read(int &x)

 {

     x = ;char ch = getchar(), c = ch;

     while(ch < '' || ch > '') c = ch, ch = getchar();

     while(ch <= '' && ch >= '') x = x *  + ch - '', ch = getchar();

     if(c == '-') x = -x;

 }

 const int INF = 0x3f3f3f3f;

 const int MAXN =  + ;

 struct Edge

 {

     int u,v,nxt;

     Edge(int _u, int _v, int _nxt){u = _u;v = _v;nxt = _nxt;}

     Edge(){}

 }edge1[MAXN << ], edge2[MAXN << ];

 int head1[MAXN], head2[MAXN], vis[MAXN], tag[MAXN], rebelong[MAXN], del[MAXN], q[MAXN], he, ta, indeg[MAXN], cnt1, cnt2, n, m, belong[MAXN], group, b[MAXN], bb[MAXN], dfn[MAXN], stack[MAXN], top, low[MAXN], dfst, year[MAXN], x, tmp1, tmp2;

 inline void insert1(int a, int b){edge1[++ cnt1] = Edge(a, b, head1[a]), head1[a] = cnt1;}

 inline void insert2(int a, int b){edge2[++ cnt2] = Edge(a, b, head2[a]), head2[a] = cnt2;}

 void dfs(int u)

 {

     b[u] = bb[u] = , dfn[u] = low[u] = ++ dfst, stack[++ top] = u;

     for(int pos = head1[u];pos;pos = edge1[pos].nxt)

     {

         int v = edge1[pos].v;

         if(!b[v]) dfs(v), low[u] = min(low[u], low[v]);

         else if(bb[v]) low[u] = min(low[u], dfn[v]);

     }

     if(low[u] == dfn[u])

     {

         int now = -;++ group;

         while(now != u) now = stack[top --], bb[now] = , belong[now] = group;

     }

 }

 void rebuild()

 {

     memset(indeg, , sizeof(indeg)), memset(head2, , sizeof(head2));

     for(int i = ;i <= cnt1;++ i)

         if(belong[edge1[i].u] != belong[edge1[i].v])

             insert2(belong[edge1[i].v], belong[edge1[i].u]), ++ indeg[belong[edge1[i].u]];

 }

 void tarjan()

 {

     memset(belong, , sizeof(belong)), memset(dfn, , sizeof(dfn)), memset(low, , sizeof(low)), group = , memset(b, , sizeof(b)), memset(bb, , sizeof(bb)), dfst = , top = , memset(rebelong, , sizeof(rebelong));

     for(int i = ;i <= n;++ i) if(!b[i << ]) dfs(i << );

     for(int i = ;i <= n;++ i) if(!b[i <<  | ]) dfs(i <<  | );

     for(int i = ;i <= n;++ i) rebelong[belong[i << ]] = belong[i <<  | ], rebelong[belong[i <<  | ]] = belong[i << ];

     rebuild();

 }

 void top_sort()

 {

     he = , ta = , memset(del, , sizeof(del));

     for(int i = ;i <= group;++ i) if(!indeg[i]) q[ta ++] = i;

     while(he < ta)

     {

         int now = q[he ++], renow = rebelong[now];

         if(del[now]) continue; del[renow] = ;

         for(int pos = head2[renow];pos;pos = edge2[pos].nxt)

         {

             int v = edge2[pos].v;

             del[v] = ;

             for(int poss = head2[v];poss;poss = edge2[poss].nxt) -- indeg[edge2[poss].v];

         }

         for(int pos = head2[now];pos;pos = edge2[pos].nxt)

         {

             int v = edge2[pos].v;

             if(del[v]) continue;

             -- indeg[v];

             if(!indeg[v]) q[ta ++] = v;

         }

     }

 }

 int main()

 {

     while(scanf("%d %d", &n, &m) != EOF && n && m)

     {

         cnt1 = , memset(head1, , sizeof(head1)), x = ;

         for(int i = ;i <= n;++ i) read(year[i]), x += year[i];

         if(x % n == ) x = x / n;

         else x = x / n + ;

         for(int i = ;i <= n;++ i) year[i] = year[i] >= x;  //year[i] = 1 表示选A或C  year[i] = 0 表示选B或C

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

         {

             read(tmp1), read(tmp2);

             if(year[tmp1] == year[tmp2]) insert1(tmp1 <<  | , tmp2 << ), insert1(tmp2 <<  | , tmp1 << ), insert1(tmp1 << , tmp2 <<  | ), insert1(tmp2 << , tmp1 <<  | );

             else insert1(tmp1 <<  | , tmp2 << ), insert1(tmp2 <<  | , tmp1 << );

         }

         tarjan();

         int flag = ;

         for(int i = ;i <= n;++ i) if(belong[i <<  | ] == belong[i << ]) flag = ;

         if(flag)

         {

             printf("No solution.\n");

             continue;

         }

         top_sort();

         memset(vis, , sizeof(vis)), memset(tag, , sizeof(tag));

         for(int i = ;i < ta;++ i) if(!del[q[i]]) vis[q[i]] = ;

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

             if(vis[belong[i << ]]) tag[i] = ;

             else tag[i] = ;

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

             if(year[i] && !tag[i]) printf("A\n");

             else if(!year[i] && !tag[i]) printf("B\n");

             else printf("C\n");

     }

     return ;

 }