import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N, K = map(int, readline().split())
S = []
C = []
for _ in range(N):
    x, y = readline().split()
    x = tuple(0 if x == 'J' else 1 if x == 'O' else 2 for x in x.decode())
    S.append(x)
    C.append(int(y))

INF = 10 ** 16
dp = [INF] * (K + K + K + 1)
dp[0] = 0

cnt = [0] * (N * 3)
for q in range(3):
    for i in range(N):
        cnt[3 * i + q] = sum(n == q for n in S[i])


def f(k, i):
    q, r = divmod(k, K)
    if k + cnt[3 * i + q] < K:
        return k + cnt[3 * i + q]
    for x in S[i]:
        if x == q:
            r += 1
            if r == K:
                r = 0
                q += 1
    return K * q + r


for k in range(K + K + K):
    for i in range(N):
        next_k = f(k, i)
        dp[next_k] = min(dp[k] + C[i], dp[next_k])

x = dp[-1]
if x == INF:
    x = -1
print(x)