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 solve_small():
    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
    return x


if K <= 100:
    print(solve_small())