#line 1 "main.cpp"
//#pragma GCC target("avx")
//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#ifdef LOCAL
#include <debug.hpp>
#define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (static_cast<void>(0))
#endif
using namespace std;
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using pii = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vpii = vector<pii>;
using vpll = vector<pll>;
using vs = vector<string>;
template<class T> using pq = priority_queue<T, vector<T>, greater<T>>;
#define overload4(_1, _2, _3, _4, name, ...) name
#define overload3(a,b,c,name,...) name
#define rep1(n) for (ll UNUSED_NUMBER = 0; UNUSED_NUMBER < (n); ++UNUSED_NUMBER)
#define rep2(i, n) for (ll i = 0; i < (n); ++i)
#define rep3(i, a, b) for (ll i = (a); i < (b); ++i)
#define rep4(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep1(n) for(ll i = (n) - 1;i >= 0;i--)
#define rrep2(i,n) for(ll i = (n) - 1;i >= 0;i--)
#define rrep3(i,a,b) for(ll i = (b) - 1;i >= (a);i--)
#define rrep4(i,a,b,c) for(ll i = (a) + ((b)-(a)-1) / (c) * (c);i >= (a);i -= c)
#define rrep(...) overload4(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define all1(i) begin(i) , end(i)
#define all2(i,a) begin(i) , begin(i) + a
#define all3(i,a,b) begin(i) + a , begin(i) + b
#define all(...) overload3(__VA_ARGS__, all3, all2, all1)(__VA_ARGS__)
#define sum(...) accumulate(all(__VA_ARGS__),0LL)
template<class T> bool chmin(T &a, const T &b){ if(a > b){ a = b; return 1; } else return 0; }
template<class T> bool chmax(T &a, const T &b){ if(a < b){ a = b; return 1; } else return 0; }
template<class T> auto min(const T& a){return *min_element(all(a));}
template<class T> auto max(const T& a){return *max_element(all(a));}
template<class... Ts> void in(Ts&... t);
#define INT(...) int __VA_ARGS__; in(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__; in(__VA_ARGS__)
#define STR(...) string __VA_ARGS__; in(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__; in(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__; in(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__; in(__VA_ARGS__)
#define VEC(type, name, size) vector<type> name(size); in(name)
#define VV(type, name, h, w) vector<vector<type>> name(h, vector<type>(w)); in(name)
ll intpow(ll a, ll b){ ll ans = 1; while(b){if(b & 1) ans *= a; a *= a; b /= 2;} return ans;}
ll modpow(ll a, ll b, ll p){ ll ans = 1; a %= p;if(a < 0) a += p;while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; }
ll GCD(ll a,ll b) { if(a == 0 || b == 0) return 0; if(a % b == 0) return b; else return GCD(b,a%b);}
ll LCM(ll a,ll b) { if(a == 0) return b; if(b == 0) return a;return a / GCD(a,b) * b;}
namespace IO{
#define VOID(a) decltype(void(a))
struct setting{ setting(){cin.tie(nullptr); ios::sync_with_stdio(false);fixed(cout); cout.precision(12);}} setting;
template<int I> struct P : P<I-1>{};
template<> struct P<0>{};
template<class T> void i(T& t){ i(t, P<3>{}); }
void i(vector<bool>::reference t, P<3>){ int a; i(a); t = a; }
template<class T> auto i(T& t, P<2>) -> VOID(cin >> t){ cin >> t; }
template<class T> auto i(T& t, P<1>) -> VOID(begin(t)){ for(auto&& x : t) i(x); }
template<class T, size_t... idx> void ituple(T& t, index_sequence<idx...>){
    in(get<idx>(t)...);}
template<class T> auto i(T& t, P<0>) -> VOID(tuple_size<T>{}){
    ituple(t, make_index_sequence<tuple_size<T>::value>{});}
#undef VOID
}
#define unpack(a) (void)initializer_list<int>{(a, 0)...}
template<class... Ts> void in(Ts&... t){ unpack(IO :: i(t)); }
#undef unpack
static const double PI = 3.1415926535897932;
template <class F> struct REC {
    F f;
    REC(F &&f_) : f(forward<F>(f_)) {}
    template <class... Args> auto operator()(Args &&...args) const { return f(*this, forward<Args>(args)...); }};
//constexpr int mod = 1000000007;
constexpr int mod = 998244353;
#include <atcoder/string>
using namespace atcoder;

template <typename T>
struct SparseTable {
  inline static constexpr T INF = numeric_limits<T>::max() / 2;
  int N;
  vector<vector<T> > table;
  T f(T a, T b) { return min(a, b); }
  SparseTable() {}
  SparseTable(const vector<T> &v) : N(v.size()) {
    int b = 1;
    while ((1 << b) <= N) ++b;
    table.push_back(v);
    for (int i = 1; i < b; i++) {
      table.push_back(vector<T>(N, INF));
      for (int j = 0; j + (1 << i) <= N; j++) {
        table[i][j] = f(table[i - 1][j], table[i - 1][j + (1 << (i - 1))]);
      }
    }
  }
  // [l, r)
  T query(int l, int r) {
    assert(0 <= l and l <= r and r <= N);
    if (l == r) return INF;
    int b = 31 - __builtin_clz(r - l);
    return f(table[b][l], table[b][r - (1 << b)]);
  }
};

#line 2 "segment-tree/segment-tree-beats.hpp"

struct AngelBeats {
  using i64 = long long;
  static constexpr i64 INF = numeric_limits<i64>::max() / 2.1;

  struct alignas(32) Node {
    i64 sum = 0, g1 = 0, l1 = 0;
    i64 g2 = -INF, gc = 1, l2 = INF, lc = 1, add = 0;
  };

  vector<Node> v;
  i64 n, log;

  AngelBeats() {}
  AngelBeats(int _n) : AngelBeats(vector<i64>(_n)) {}
  AngelBeats(const vector<i64>& vc) {
    n = 1, log = 0;
    while (n < (int)vc.size()) n <<= 1, log++;
    v.resize(2 * n);
    for (i64 i = 0; i < (int)vc.size(); ++i) {
      v[i + n].sum = v[i + n].g1 = v[i + n].l1 = vc[i];
    }
    for (i64 i = n - 1; i; --i) update(i);
  }

  void range_chmin(int l, int r, i64 x) { inner_apply<1>(l, r, x); }
  void range_chmax(int l, int r, i64 x) { inner_apply<2>(l, r, x); }
  void range_add(int l, int r, i64 x) { inner_apply<3>(l, r, x); }
  void range_update(int l, int r, i64 x) { inner_apply<4>(l, r, x); }
  i64 range_min(int l, int r) { return inner_fold<1>(l, r); }
  i64 range_max(int l, int r) { return inner_fold<2>(l, r); }
  i64 range_sum(int l, int r) { return inner_fold<3>(l, r); }

 private:
  void update(int k) {
    Node& p = v[k];
    Node& l = v[k * 2 + 0];
    Node& r = v[k * 2 + 1];

    p.sum = l.sum + r.sum;

    if (l.g1 == r.g1) {
      p.g1 = l.g1;
      p.g2 = max(l.g2, r.g2);
      p.gc = l.gc + r.gc;
    } else {
      bool f = l.g1 > r.g1;
      p.g1 = f ? l.g1 : r.g1;
      p.gc = f ? l.gc : r.gc;
      p.g2 = max(f ? r.g1 : l.g1, f ? l.g2 : r.g2);
    }

    if (l.l1 == r.l1) {
      p.l1 = l.l1;
      p.l2 = min(l.l2, r.l2);
      p.lc = l.lc + r.lc;
    } else {
      bool f = l.l1 < r.l1;
      p.l1 = f ? l.l1 : r.l1;
      p.lc = f ? l.lc : r.lc;
      p.l2 = min(f ? r.l1 : l.l1, f ? l.l2 : r.l2);
    }
  }

  void push_add(int k, i64 x) {
    Node& p = v[k];
    p.sum += x << (log + __builtin_clz(k) - 31);
    p.g1 += x;
    p.l1 += x;
    if (p.g2 != -INF) p.g2 += x;
    if (p.l2 != INF) p.l2 += x;
    p.add += x;
  }
  void push_min(int k, i64 x) {
    Node& p = v[k];
    p.sum += (x - p.g1) * p.gc;
    if (p.l1 == p.g1) p.l1 = x;
    if (p.l2 == p.g1) p.l2 = x;
    p.g1 = x;
  }
  void push_max(int k, i64 x) {
    Node& p = v[k];
    p.sum += (x - p.l1) * p.lc;
    if (p.g1 == p.l1) p.g1 = x;
    if (p.g2 == p.l1) p.g2 = x;
    p.l1 = x;
  }
  void push(int k) {
    Node& p = v[k];
    if (p.add != 0) {
      push_add(k * 2 + 0, p.add);
      push_add(k * 2 + 1, p.add);
      p.add = 0;
    }
    if (p.g1 < v[k * 2 + 0].g1) push_min(k * 2 + 0, p.g1);
    if (p.l1 > v[k * 2 + 0].l1) push_max(k * 2 + 0, p.l1);

    if (p.g1 < v[k * 2 + 1].g1) push_min(k * 2 + 1, p.g1);
    if (p.l1 > v[k * 2 + 1].l1) push_max(k * 2 + 1, p.l1);
  }

  void subtree_chmin(int k, i64 x) {
    if (v[k].g1 <= x) return;
    if (v[k].g2 < x) {
      push_min(k, x);
      return;
    }
    push(k);
    subtree_chmin(k * 2 + 0, x);
    subtree_chmin(k * 2 + 1, x);
    update(k);
  }

  void subtree_chmax(int k, i64 x) {
    if (x <= v[k].l1) return;
    if (x < v[k].l2) {
      push_max(k, x);
      return;
    }
    push(k);
    subtree_chmax(k * 2 + 0, x);
    subtree_chmax(k * 2 + 1, x);
    update(k);
  }

  template <int cmd>
  inline void _apply(int k, i64 x) {
    if constexpr (cmd == 1) subtree_chmin(k, x);
    if constexpr (cmd == 2) subtree_chmax(k, x);
    if constexpr (cmd == 3) push_add(k, x);
    if constexpr (cmd == 4) subtree_chmin(k, x), subtree_chmax(k, x);
  }

  template <int cmd>
  void inner_apply(int l, int r, i64 x) {
    if (l == r) return;
    l += n, r += n;
    for (int i = log; i >= 1; i--) {
      if (((l >> i) << i) != l) push(l >> i);
      if (((r >> i) << i) != r) push((r - 1) >> i);
    }
    {
      int l2 = l, r2 = r;
      while (l < r) {
        if (l & 1) _apply<cmd>(l++, x);
        if (r & 1) _apply<cmd>(--r, x);
        l >>= 1;
        r >>= 1;
      }
      l = l2;
      r = r2;
    }
    for (int i = 1; i <= log; i++) {
      if (((l >> i) << i) != l) update(l >> i);
      if (((r >> i) << i) != r) update((r - 1) >> i);
    }
  }

  template <int cmd>
  inline i64 e() {
    if constexpr (cmd == 1) return INF;
    if constexpr (cmd == 2) return -INF;
    return 0;
  }

  template <int cmd>
  inline void op(i64& a, const Node& b) {
    if constexpr (cmd == 1) a = min(a, b.l1);
    if constexpr (cmd == 2) a = max(a, b.g1);
    if constexpr (cmd == 3) a += b.sum;
  }

  template <int cmd>
  i64 inner_fold(int l, int r) {
    if (l == r) return e<cmd>();
    l += n, r += n;
    for (int i = log; i >= 1; i--) {
      if (((l >> i) << i) != l) push(l >> i);
      if (((r >> i) << i) != r) push((r - 1) >> i);
    }
    i64 lx = e<cmd>(), rx = e<cmd>();
    while (l < r) {
      if (l & 1) op<cmd>(lx, v[l++]);
      if (r & 1) op<cmd>(rx, v[--r]);
      l >>= 1;
      r >>= 1;
    }
    if constexpr (cmd == 1) lx = min(lx, rx);
    if constexpr (cmd == 2) lx = max(lx, rx);
    if constexpr (cmd == 3) lx += rx;
    return lx;
  }
};

/**
 * @brief Range Chmin Chmax Add Update Range Min Max Sum Segment Tree Beats!
 * @docs docs/segment-tree/segment-tree-beats.md
 */
int main() {
    INT(n,q);
    STR(s);
    vi L(q),R(q);
    rep(i,q) {
        cin >> L[i] >> R[i];
        L[i]--;
    }
    auto sa = suffix_array(s);
    auto lcp = lcp_array(s,sa);
    auto spt = SparseTable<int>(lcp);
    vl ans(q);
    debug(ord);
    int cur = 0;
    vl init(n,1e9);
    AngelBeats abseg(init);
    debug(ans);
    vector<vpii> evt(n);
    rep(i,q) evt[L[i]].emplace_back(i,R[i]);
    rrep(i,n) {
        if(i < n - 1) abseg.range_chmin(i+1,n,lcp[i]);
        int l = sa[i];
        for(auto &[id,r]:evt[l]) {
            int len = r - l;
            int ng = n;
            int ok = i;
            while(ng - ok > 1) {
                int mid = (ng + ok) / 2;
                debug(mid);
                int lc = spt.query(i,mid);
                if(lc >= len) ok = mid;
                else ng = mid;
            }
            //debug(i,l,r,ok,ng);
            ans[id] += 1LL * (ok - i) * (r - l - 1);
            ans[id] += abseg.range_sum(ok+1,n);
        }
    }
    vl cs(n+1);
    rep(i,n) cs[i+1] = cs[i] + (n - sa[i]);
    AngelBeats abseg2(init);
    rep(i,n) {
        if(i > 0) abseg2.range_chmin(0,i,lcp[i-1]);
        int l = sa[i];
        for(auto &[id,r]:evt[l]) {
            int len = r - l;
            int ng = -1;
            int ok = i;
            while(ok - ng > 1) {
                int mid = (ng + ok) / 2;
                debug(mid);
                int lc = spt.query(mid,i);
                if(lc >= len) ok = mid;
                else ng = mid;
            }
            ans[id] += 1LL * (i + 1 - ok) * (r - l - 1);
            ans[id] += cs[ok];
        }
    }
    rep(i,q) cout << ans[i] << '\n';
}