from bisect 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+=[*str(i)],
idx={}
for i in'123456789':
  idx[i]=[]
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
  bs=[-1]*10
  for i in range(1,10):
    bs[i]=bisect(idx[str(i)],r-1)-1
  for st in e:
    if m!=len(st):
      continue
    p={}
    a=0
    pos=r-1
    mv=[]
    for j in range(m):
      ns=st[~j]
      k=bs[int(ns)]
      if ns not in p:
        p[ns]=0
      if 0<=k-p[ns]<len(idx[ns])and l<=idx[ns][k-p[ns]]:
        nxt=idx[ns][k-p[ns]]
        for t in mv:
          if t<idx[ns][k-p[ns]]:
            nxt-=1
        a+=abs(pos-nxt)
        mv+=idx[ns][k-p[ns]],
        p[ns]+=1
      else:
        a=INF
        break
      pos-=1
    ans=min(ans,a)
  print([-1,ans][ans<INF])