N,K = map(int,input().split())
CS = []
for _ in range(N):
    s,c = input().split()
    CS.append([int(c),list(s)])
inf =10**18
DPJ = [inf]*(K+1)
DPO = [inf]*(K+1)
DPI = [inf]*(K+1)
DPJ[0] = 0
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)])
                elif J>=K:
                    DPO[O]=min(DPJ[i]+c,DPO[O])
            elif DPJ[i+cnt]>DPJ[i]+c:
                DPJ[i+cnt]=DPJ[i]+c
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
                if O>=K:
                    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])