// URL: https://yukicoder.me/problems/no/762

import std.algorithm, std.array, std.container, std.math, std.range, std.typecons, std.string;

version(unittest) {} else
void main()
{
  int N, M; io.getV(N, M);
  string S; io.getV(S);

  auto g = Graph(N);
  foreach (_; 0..M) {
    int u, v; io.getV(u, v); --u; --v;
    g.addEdgeB(u, v);
  }

  auto p = new mint[](N), d = new mint[](N), c = new mint[](N), a = new mint[](N);

  foreach (i; 0..N)
    if (S[i] == 'P')
      p[i] = 1;

  foreach (i; 0..N)
    if (S[i] == 'P')
      foreach (j; g[i])
        if (S[j] == 'D')
          d[j] += p[i];

  foreach (i; 0..N)
    if (S[i] == 'D')
      foreach (j; g[i])
        if (S[j] == 'C')
          c[j] += d[i];

  foreach (i; 0..N)
    if (S[i] == 'C')
      foreach (j; g[i])
        if (S[j] == 'A')
          a[j] += c[i];

  io.put(a.sum);
}

struct Graph
{
  alias Node = int;
  Node n;
  Node[][] g;
  alias g this;
  this(Node n) { this.n = n; g = new Node[][](n); }
  void addEdge(Node u, Node v) { g[u] ~= v; }
  void addEdgeB(Node u, Node v) { g[u] ~= v; g[v] ~= u; }
}

struct GraphW(W = int, W i = 10^^9)
{
  alias Node = int, Wt = W, inf = i;
  struct Edge { Node src, dst; Wt wt; alias cap = wt; }
  Node n;
  Edge[][] g;
  alias g this;
  this(Node n) { this.n = n; g = new Edge[][](n); }
  void addEdge(Node u, Node v, Wt w) { g[u] ~= Edge(u, v, w); }
  void addEdgeB(Node u, Node v, Wt w) { g[u] ~= Edge(u, v, w); g[v] ~= Edge(v, u, w); }
}

struct GraphM(W = int, W i = 10^^9)
{
  alias Node = int, Wt = W, inf = i;
  Node n;
  Wt[][] g;
  alias g this;
  this(int n) { this.n = n; g = new Wt[][](n, n); }
  static GraphM!(W, i) init(Node n)
  {
    auto g = GraphM!(W, i)(n);
    foreach (i; 0..n) { g[i][] = inf; g[i][i] = 0; }
    return g;
  }
}

const mod = 10^^9+7;
alias mint = ModInt!mod;
auto lowerBoundBy(alias conv = "a", alias comp = "a<b", R, T)(R a, T v)
{ return a.sortedTuple!(conv, comp).lowerBound(tuple(a.front, v)).map!"a[0]"; }

auto upperBoundBy(alias conv = "a", alias comp = "a<b", R, T)(R a, T v)
{ return a.sortedTuple!(conv, comp).upperBound(tuple(a.front, v)).map!"a[0]"; }

auto sortedTuple(alias conv = "a", alias comp = "a<b", R)(R a)
{
  import std.functional;
  alias convFun = unaryFun!conv, compFun = binaryFun!comp;
  return a.map!(e => tuple(e, convFun(e))).assumeSorted!((a, b) => compFun(a[1], b[1]));
}

pure T isqrt(T)(T n)
{
  static if (is(T == int)) auto max = 46341;
  else static if (is(T == long)) auto max = 3037000500L;
  return iota(T(0), max).lowerBoundBy!("a^^2", "a<=b")(n).back;
}

pure T icbrt(T)(T n)
{
  static if (is(T == int)) auto max = 1291;
  else static if (is(T == long)) auto max = 2097152L;
  return iota(T(0), max).lowerBoundBy!("a^^3", "a<=b")(n).back;
}

pure T powr(alias pred = "a*b", T, U)(T a, U n, T one)
{
  import std.functional;
  alias predFun = binaryFun!pred;
  if (n == 0) return one;
  auto r = one;
  for (; n > 0; n >>= 1) { if (n&1) r = predFun(r, a); a = predFun(a, a); }
  return r;
}
pure T powr(alias pred = "a*b", T, U)(T a, U n) { return powr!(pred, T, U)(a, n, T(1)); }

pure T extGcd(T)(T a, T b, out T x, out T y)
{
  auto g = a; x = 1; y = 0;
  if (b) { g = extGcd(b, a%b, y, x); y -= a/b*x; }
  return g;
}

struct ModInt(int m, bool pos = false)
{
  version(BigEndian) union { long l; struct { int i2; int i; } } else union { long l; int i; }
  alias M = ModInt!(m, pos), Op = string;
  @property static init() { return M(0); }
  @property int value() { return i; }
  @property void value(int v) { i = nm(v); }
  alias value this;

  this(T)(T v = 0) { i = nm(v); }
  ref M opAssign(T)(T v) { i = nm(v); return this; }

  static if (!pos) pure M opUnary(Op op: "-")() { return M(-i); }

  static if (m < int.max / 2) {
    pure M opBinary(Op op)(int r) if(op=="+"||!pos&&op=="-") { return M(mixin("i"~op~"r")); }
    ref M opOpAssign(Op op)(int r) if(op=="+"||!pos&&op=="-") { i=nm(mixin("i"~op~"r")); return this; }
  } else {
    pure M opBinary(Op op)(int r) if(op=="+"||!pos&&op=="-") { return M(mixin("l"~op~"r")); }
    ref M opOpAssign(Op op)(int r) if(op=="+"||!pos&&op=="-") { i=nm(mixin("l"~op~"r")); return this; }
  }
  pure M opBinary(Op op: "*")(int r) { return M(l*r); }
  ref M opOpAssign(Op op: "*")(int r) { i=nm(l*r); return this; }

  pure M opBinary(Op op)(M r) if(op=="+"||!pos&&op=="-"||op=="*") { return opBinary!op(r.i); }
  ref M opOpAssign(Op op)(M r) if(op=="+"||!pos&&op=="-"||op=="*") { return opOpAssign!op(r.i); }

  pure M opBinary(Op op: "^^", T)(T n) { return this.powr(n); }

  static if (!pos) {
    pure M opBinary(Op op: "/")(M r) { return M(l*r.inv.i); }
    ref M opOpAssign(Op op: "/")(M r) { i=nm(l*r.inv.i); return this; }

    pure M opBinary(Op op: "/")(int r) { return opBinary!op(M(r)); }
    ref M opOpAssign(Op op: "/")(int r) { return opOpAssign!op(M(r)); }

    pure M inv() { int x = i, a, b; extGcd(x, m, a, b); return M(a); }
  }

  private
  {
    pure int nm(int v) { static if (pos) return v%m; else return (v%m+m)%m; }
    pure int nm(long v) { static if (pos) return cast(int)(v%m); else return cast(int)((v%m+m)%m); }
  }
}

auto io = IO!()();
import std.stdio;
struct IO(alias IN = stdin, alias OUT = stdout)
{
  import std.conv, std.format, std.meta, std.traits, core.stdc.stdlib;

  auto getV(T...)(ref T v) { foreach (ref w; v) get(w); }
  auto getA(T)(size_t n, ref T v) if (hasAssignableElements!T)
  { v = new T(n); foreach (ref w; v) get(w); }
  auto getC(T...)(size_t n, ref T v)
  if (allSatisfy!(hasAssignableElements, T))
  {
    foreach (ref w; v) w = new typeof(w)(n);
    foreach (i; 0..n) foreach (ref w; v) get(w[i]);
  }
  auto getM(T)(size_t r, size_t c, ref T v)
  if (hasAssignableElements!T && hasAssignableElements!(ElementType!T))
  { v = new T(r); foreach (ref w; v) getA(c, w); }
  template getS(E...)
  {
    auto getS(T)(size_t n, ref T v)
    { v = new T(n); foreach (ref w; v) foreach (e; E) mixin("get(w."~e~");"); }
  }

  const struct PutConf
  {
    bool newline = true, flush, exit;
    string floatFormat = "%.10f", delimiter = " ";
  }

  auto put(alias conf = "{}", T...)(T v)
  { mixin("const PutConf c = "~conf~"; putMain!c(v);"); }
  auto putB(alias conf = "{}", S, T)(bool c, S t, T f)
  { if (c) put(t); else put(f); }
  auto putRaw(T...)(T v) { OUT.write(v); OUT.writeln; }

  private
  {
    dchar[] buf;
    auto sp = (new dchar[](0)).splitter;
    void nextLine() { IN.readln(buf); sp = buf.splitter; }
    auto get(T)(ref T v) { if (sp.empty) nextLine(); v = sp.front.to!T; sp.popFront(); }

    auto putMain(PutConf c, T...)(T v)
    {
      foreach (i, w; v) {
        putOne!c(w);
        if (i < v.length-1) OUT.write(c.delimiter);
      }
      static if (c.newline) OUT.writeln;
      static if (c.flush) OUT.flush();
      static if (c.exit) exit(0);
    }
    auto putOne(PutConf c, T)(T v)
    {
      static if (isInputRange!T && !isSomeString!T) putRange!c(v);
      else if (isFloatingPoint!T) OUT.write(format(c.floatFormat, v));
      else OUT.write(v);
    }
    auto putRange(PutConf c, T)(T v)
    {
      auto w = v;
      while (!w.empty) {
        putOne!c(w.front); w.popFront();
        if (!w.empty) OUT.write(c.delimiter);
      }
    }
  }
}