N,K = map(int,input().split())
CS = []
for _ in range(N):
    s,c = input().split()
    CS.append([int(c),list(s)])
CS = sorted(CS, key=lambda x: x[0])
inf =10**18
DPJ = [inf]*(K+1)
DPO = [inf]*(K+1)
DPI = [inf]*(K+1)
DPJ[0] = 0
for _ in range(2):
    for c,S in CS:
        cnt = S.count('J')
        if cnt==0:
            continue
        for i in range(K):
            if DPJ[i]!=inf:
                if i+cnt>=K:
                    J=i
                    O=0
                    I=0
                    for s in S:
                        if J<K and s=='J':
                            J+=1
                        if J>=K and s=='O':
                            O+=1
                        if O>=K and s=='I':
                            I+=1
                    if O>=K:
                        DPI[min(K,I)]=min(DPJ[i]+c,DPI[min(K,I)])
                    else:
                        DPO[O]=min(DPJ[i]+c,DPO[O])
                elif DPJ[i+cnt]>DPJ[i]+c:
                    DPJ[i+cnt]=DPJ[i]+c
for _ in range(2):
    for c,S in CS:
        cnt = S.count('O')
        if cnt==0:
            continue
        for i in range(K):
            if DPO[i]!=inf:
                if i+cnt>=K:
                    O=i
                    I=0
                    for s in S:
                        if s=='O':
                            O+=1
                        if O>=K and s=='I':
                            I+=1
                    DPI[min(K,I)]=min(DPO[i]+c,DPI[min(K,I)])
                elif DPO[i+cnt]>DPO[i]+c:
                    DPO[i+cnt]=DPO[i]+c

for c,S in CS:
    cnt = S.count('I')
    if cnt==0:
        continue
    for i in range(K):
        if DPI[i]!=inf:
            if  DPI[min(K,i+cnt)]>DPI[i]+c:
                DPI[min(K,i+cnt)]=DPI[i]+c

if DPI[-1]==inf:
    print(-1)
else:
    print(DPI[-1])