#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
namespace Mymath {
long long qp(long long x, long long p, long long mod) {
  long long ans = 1;
  while (p) {
    if (p & 1) ans = ans * x % mod;
    x = x * x % mod;
    p >>= 1;
  }
  return ans;
}
long long inv(long long x, long long mod) { return qp(x, mod - 2, mod); }
long long C(long long N, long long K, long long fact[], long long mod) {
  return fact[N] * inv(fact[K], mod) % mod * inv(fact[N - K], mod) % mod;
}
template <typename Tp>
Tp gcd(Tp A, Tp B) {
  if (B == 0) return A;
  return gcd(B, A % B);
}
template <typename Tp>
Tp lcm(Tp A, Tp B) {
  return A * B / gcd(A, B);
}
};  // namespace Mymath
namespace fwt {
using namespace Mymath;
void FWT(int a[], int n, long long mod) {
  for (int d = 1; d < n; d <<= 1)
    for (int m = d << 1, i = 0; i < n; i += m)
      for (int j = 0; j < d; j++) {
        int x = a[i + j], y = a[i + j + d];
        a[i + j] = (x + y) % mod, a[i + j + d] = (x - y + mod) % mod;
      }
}
void UFWT(int a[], int n, long long mod) {
  long long rev = inv(2, mod);
  for (int d = 1; d < n; d <<= 1)
    for (int m = d << 1, i = 0; i < n; i += m)
      for (int j = 0; j < d; j++) {
        int x = a[i + j], y = a[i + j + d];
        a[i + j] = 1LL * (x + y) * rev % mod,
              a[i + j + d] = (1LL * (x - y) * rev % mod + mod) % mod;
      }
}
void solve(int a[], int b[], int n, long long mod) {
  FWT(a, n, mod);
  FWT(b, n, mod);
  for (int i = 0; i < n; i++) a[i] = 1LL * a[i] * b[i] % mod;
  UFWT(a, n, mod);
}
};  // namespace fwt
namespace Maxflow {
const int Maxn = 1005;
struct edge {
  int to, rev, cap;
  edge(int _to, int _rev, int _cap) { to = _to, rev = _rev, cap = _cap; }
};
int src = 1002, snk = 1003;
vector<edge> G[Maxn];
int dist[Maxn], seen[Maxn];
int n;
void Clear() {
  for (int i = 0; i < Maxn; i++) G[i].clear();
}
void bfs(int s) {
  for (int i = 0; i < Maxn; i++) dist[i] = -1;
  dist[s] = 0;
  queue<int> Q;
  Q.push(s);
  while (!Q.empty()) {
    int x = Q.front();
    Q.pop();
    for (int i = 0; i < G[x].size(); i++) {
      edge &e = G[x][i];
      if (e.cap && dist[e.to] == -1) {
        dist[e.to] = dist[x] + 1;
        Q.push(e.to);
      }
    }
  }
}
int dfs(int now, int dest, int fl) {
  if (now == dest) return fl;
  for (int &i = seen[now]; i < G[now].size(); i++) {
    edge &ed = G[now][i];
    if (ed.cap && dist[ed.to] == dist[now] + 1) {
      int f = dfs(ed.to, dest, min(fl, ed.cap));
      if (f) {
        ed.cap -= f;
        G[ed.to][ed.rev].cap += f;
        return f;
      }
    }
  }
  return 0;
}
int dinic(int s = src, int t = snk) {
  int ret = 0;
  while (1) {
    memset(seen, 0, sizeof(seen));
    bfs(s);
    if (dist[t] == -1) return ret;
    int f = dfs(s, t, 2147483647);
    while (f) {
      ret += f;
      f = dfs(s, t, 2147483647);
    }
  }
}
};  // namespace Maxflow
namespace Geometry {
struct iP {
  long long x, y;
  iP(long long _x, long long _y) { x = _x, y = _y; }
  iP() { x = y = 0; }
  iP operator+(iP p) { return iP(x + p.x, y + p.y); }
  iP operator-(iP p) { return iP(x - p.x, y - p.y); }
  iP operator*(long long k) { return iP(x * k, y * k); }
  long long det(iP p) { return x * p.y - y * p.x; }
  long long dot(iP p) { return x * p.x + y * p.y; }
  long long dist() { return x * x + y * y; }
  bool operator<(const iP &p) const {
    if (x != p.x) return x < p.x;
    return y < p.y;
  }
};
struct dP {
  double x, y;
  dP(double _x, double _y) { x = _x, y = _y; }
  dP() { x = y = 0.0; }
  dP operator+(dP p) { return dP(x + p.x, y + p.y); }
  dP operator-(dP p) { return dP(x - p.x, y - p.y); }
  dP operator*(double k) { return dP(x * k, y * k); }
  double det(dP p) { return x * p.y - y * p.x; }
  double dot(dP p) { return x * p.x + y * p.y; }
  double dist() { return x * x + y * y; }
  bool operator<(const dP &p) const {
    if (x != p.x) return x < p.x;
    return y < p.y;
  }
};
vector<iP> convex_hull(iP X[], int l) {
  vector<iP> ret;
  sort(X + 1, X + 1 + l);
  ret.push_back(X[1]);
  for (int i = 2; i <= l; i++) {
    while (ret.size() >= 2 &&
           (ret[ret.size() - 2] - X[i]).det(ret[ret.size() - 1] - X[i]) >= 0) {
      ret.pop_back();
    }
    ret.push_back(X[i]);
  }
  int rs = ret.size() + 1;
  for (int i = l - 1; i >= 1; i--) {
    while (ret.size() >= rs &&
           (ret[ret.size() - 2] - X[i]).det(ret[ret.size() - 1] - X[i]) >= 0) {
      ret.pop_back();
    }
    ret.push_back(X[i]);
  }
  return ret;
}
};  // namespace Geometry
const int Maxn = 2e5 + 5;
const int Maxm = 5500005;
int n, q;
int a[Maxn];
bool isp[Maxm];
vector<int> P;
vector<int> p[Maxn];
void _init() {
  memset(isp, true, sizeof(isp));
  isp[0] = isp[1] = false;
  for (int i = 2; i < Maxm; i++) {
    if (isp[i]) {
      P.push_back(i);
      for (int j = i + i; j < Maxm; j += i) {
        isp[j] = false;
      }
    }
  }
}
long long Ha(vector<int> &V) {
  long long ret = 12384722;
  for (int i = 0; i < V.size(); i++) {
    ret = ret * 94333337 + V[i];
  }
  return ret;
}
vector<long long> H[Maxn];
struct node {
  vector<pair<int, int> > st;
  long long hh;
  node *nxt;
  node(long long _hh) {
    hh = _hh;
    nxt = NULL;
    st.clear();
  }
};
const int ss = 5000000;
node *Mp[ss];
void Add(long long HH, int Siz, int Pos) {
  long long pp = HH % (long long)ss;
  if (pp < 0) pp += ss;
  if (Mp[pp] == NULL) {
    Mp[pp] = new node(HH);
    Mp[pp]->st.push_back(make_pair(Siz, Pos));
    return;
  }
  node *tmp = Mp[pp];
  bool Find = false;
  while (tmp) {
    if (tmp->hh == HH) {
      Find = true;
      break;
    }
    if (tmp->nxt == NULL) break;
    tmp = tmp->nxt;
  }
  if (Find) {
    while (!tmp->st.empty() && tmp->st.back().first >= Siz) {
      tmp->st.pop_back();
    }
    tmp->st.push_back(make_pair(Siz, Pos));
    return;
  }
  tmp->nxt = new node(HH);
  tmp->nxt->st.push_back(make_pair(Siz, Pos));
}
vector<pair<int, int> > Get(long long HH) {
  long long pp = HH % ss;
  if (pp < 0) pp += ss;
  vector<pair<int, int> > ept;
  if (!Mp[pp]) return ept;
  node *tmp = Mp[pp];
  while (tmp) {
    if (tmp->hh == HH) return tmp->st;
    if (tmp->nxt == NULL) return ept;
    tmp = tmp->nxt;
  }
  return ept;
}
void Ckm(int &x, int y) {
  if (y < x) x = y;
}
int imp[Maxn][19];
vector<pair<int, int> > Q[Maxn];
int ans[2000000];
int tree[Maxn * 4], tag[Maxn * 4];
void Push(int p) {
  tag[p * 2] = min(tag[p * 2], tag[p]);
  tag[p * 2 + 1] = min(tag[p * 2 + 1], tag[p]);
  tree[p * 2] = min(tree[p * 2], tag[p]);
  tree[p * 2 + 1] = min(tree[p * 2 + 1], tag[p]);
  tag[p] = 1e9;
}
void modify(int p, int l, int r, int lo, int hi, int val) {
  if (lo > hi) return;
  if (hi > r) hi = r;
  if (lo <= l && r <= hi) {
    tag[p] = min(tag[p], val);
    tree[p] = min(tree[p], val);
    return;
  }
  Push(p);
  int mid = l + r >> 1;
  if (lo <= mid) {
    modify(p * 2, l, mid, lo, min(hi, mid), val);
  }
  if (hi > mid) {
    modify(p * 2 + 1, mid + 1, r, max(lo, mid + 1), hi, val);
  }
  tree[p] = min(tree[p * 2], tree[p * 2 + 1]);
}
int query(int p, int l, int r, int lo, int hi) {
  if (lo > hi) return 1e9;
  if (lo <= l && r <= hi) {
    return tree[p];
  }
  Push(p);
  int mid = l + r >> 1;
  int ans = 1e9;
  if (lo <= mid) {
    ans = min(ans, query(p * 2, l, mid, lo, min(hi, mid)));
  }
  if (hi > mid) {
    ans = min(ans, query(p * 2 + 1, mid + 1, r, max(lo, mid + 1), hi));
  }
  tree[p] = min(tree[p * 2], tree[p * 2 + 1]);
  return ans;
}
int main() {
  _init();
  n = read();
  q = read();
  for (int i = 1; i <= n; i++) {
    a[i] = read();
    int tmp = a[i];
    for (int j = 0; j < P.size(); j++) {
      if (P[j] * P[j] > tmp) break;
      int f = 0;
      while (tmp % P[j] == 0) {
        tmp /= P[j];
        f ^= 1;
      }
      if (f) p[i].push_back(P[j]);
    }
    if (tmp != 1) p[i].push_back(tmp);
    int s = p[i].size();
    vector<int> T;
    for (int j = 0; j < (1 << s); j++) {
      T.clear();
      for (int k = 0; k < s; k++) {
        if (j >> k & 1) T.push_back(p[i][k]);
      }
      H[i].push_back(Ha(T));
    }
  }
  for (int i = n; i >= 1; i--) {
    int s = p[i].size();
    vector<int> T;
    for (int j = 0; j < 16; j++) imp[i][j] = 1e9;
    for (int j = 0; j < (1 << s); j++) {
      int vv = __builtin_popcount(j);
      vector<pair<int, int> > GG = Get(H[i][j]);
      for (int k = 0; k < GG.size(); k++) {
        Ckm(imp[i][s - vv * 2 + GG[k].first], GG[k].second);
      }
    }
    for (int j = 0; j < H[i].size(); j++) {
      Add(H[i][j], s, i);
    }
    for (int j = 1; j < 16; j++) {
      imp[i][j] = min(imp[i][j], imp[i][j - 1]);
    }
  }
  for (int i = 0; i < q; i++) {
    int l, r;
    l = read();
    r = read();
    Q[l].push_back(make_pair(r, i));
  }
  for (int i = 0; i < 4 * Maxn; i++) {
    tag[i] = 1e9;
    tree[i] = 1e9;
  }
  for (int i = n; i >= 1; i--) {
    if (i != n) {
      int lst = i + 1;
      for (int j = 14; j >= 0; j--) {
        if (imp[i][j] == imp[i][j + 1]) continue;
        modify(1, 1, n, lst, imp[i][j] - 1, j + 1);
        lst = imp[i][j];
      }
      modify(1, 1, n, lst, n, 0);
    }
    for (int j = 0; j < Q[i].size(); j++) {
      int id = Q[i][j].second, r = Q[i][j].first;
      ans[id] = query(1, 1, n, i + 1, r);
    }
  }
  for (int i = 0; i < q; i++) {
    printf("%d\n", ans[i]);
  }
  return ~~(0 ^ 0 ^ 0);
}
