#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, q;
  cin >> n >> q;
  string s;
  cin >> s;
  reverse(all(s));
  VI pos[10];
  rep(i, n) pos[s[i] - '0'].emplace_back(i);
  vector<array<int, 3>> cand;
  for (int x = 0; x < 1000; x += 8) {
    string s = to_string(x);
    if (s.size() != 3 || count(all(s), '0')) continue;
    reverse(all(s));
    cand.push_back({s[0] - '0', s[1] - '0', s[2] - '0'});
  }
  constexpr int INF = 1001001001;
  rep(_, q) {
    int l, r;
    cin >> l >> r;
    l--;
    tie(l, r) = pair(n - r, n - l);
    span<int> d[10];
    rep(x, 10) d[x] = span(ranges::lower_bound(pos[x], l), ranges::lower_bound(pos[x], r));
    int ans = INF;
    int nxt[10]{};
    for (auto a : cand) {
      rep(i, 3) nxt[a[i]] = 0;
      int p[3]{};
      bool ok = true;
      rep(i, 3) {
        int x = a[i];
        if (nxt[x] == ssize(d[x])) {
          ok = false;
          break;
        }
        p[i] = d[x][nxt[x]++] - l;
      }
      if (!ok) continue;
      int cost = 0;
      rep(i, 3) {
        for (int j = i + 1; j < 3; j++) if (p[j] < p[i]) p[j]++;
        cost += p[i] - i;
      }
      chmin(ans, cost);
    }
    if (ans == INF) ans = -1;
    cout << ans << '\n';
  }
}