#region Header
#!/usr/bin/env python3
# from typing import *

import sys
import io
import math
import collections
import decimal
import itertools
from queue import PriorityQueue
import bisect
import heapq

def input():
    return sys.stdin.readline()[:-1]

sys.setrecursionlimit(1000000)
#endregion

# _INPUT = """# paste here...
# """
# sys.stdin = io.StringIO(_INPUT)

MOD = 1000000007

# def solve(N: int, M: int, S: str, u: List[int], v: List[int]) -> int:
def solve(N, M, S, u, v):
    pass  # TODO: edit here

def main():
    N, M = map(int, input().split())
    S = input()
    G = [list() for _ in range(N)]
    for _ in range(M):
        _u, _v = map(int, input().split())
        G[_u-1].append(_v-1)
        G[_v-1].append(_u-1)

    count = 0
    for i in range(N):
        if S[i] == 'P':
            for j in G[i]:
                if S[j] == 'D':
                    for k in G[j]:
                        if S[k] == 'C':
                            for l in G[k]:
                                if S[l] == 'A':
                                    count += 1
    print(count)

if __name__ == '__main__':
    main()