from bisect import*
from collections import*
n,q=map(int,input().split())
s=input()
e=[]
for i in range(1000):
  if i%8==0 and'0'not in str(i):
    e+=i,
idx=defaultdict(list)
for i in range(n):
  idx[s[i]]+=i,
INF=1<<60
for _ in range(q):
  l,r=map(int,input().split())
  l-=1
  d=r-l
  m=min(d,3)
  ans=INF
  for i in e:
    st=[*str(i)]
    if m!=len(st):
      continue
    p=defaultdict(int)
    a=0
    pos=r-1
    while st:
      ns=st.pop()
      k=bisect(idx[ns],pos)-1
      if 0<=k-p[ns]<len(idx[ns])and l<=idx[ns][k-p[ns]]:
        a+=pos-idx[ns][k-p[ns]]
        p[ns]+=1
      else:
        a=INF
        break
      pos-=1
    ans=min(ans,a)
  print([-1,ans][ans<INF])