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#include <bits/stdc++.h>
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using namespace std;
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using ll = long long;
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const int N = 50000 + 1;
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int n, m;
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int col[N];
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int block;
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int cnt[N];
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ll ans1[N], ans2[N];
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ll sum;
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struct query {
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    ll l, r, id;
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    bool operator<(const query& q) const {
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        int bl = l / block;
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        int br = q.l / block;
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        if (bl != br) return bl < br;
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        if (bl & 1) return r < q.r;
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        return r > q.r;
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    }
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} a[N];
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ll gcd(ll a, ll b) {
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    return b ? gcd(b, a % b) : a;
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}
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void add(int x) {
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    sum += cnt[col[x]];
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    ++cnt[col[x]];
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}
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void del(int x) {
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    sum -= (cnt[col[x]] - 1);
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    --cnt[col[x]];
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}
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void solve() {
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    cin >> n >> m;
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    if (m == 0) return;
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    block = int(n / sqrt(m)) + 1;
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    for (int i = 1; i <= n; ++i) cin >> col[i];
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    for (int i = 0; i < m; ++i) {
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        cin >> a[i].l >> a[i].r;
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        a[i].id = i;
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    }
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    sort(a, a + m);
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    for (ll i = 0, l = 1, r = 0; i < m; ++i) {
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        query& q = a[i];
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        while (l > q.l) add(--l);
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        while (r < q.r) add(++r);
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        while (l < q.l) del(l++);
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        while (r > q.r) del(r--);
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        ans1[q.id] = sum;
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        ans2[q.id] = (r - l + 1) * (r - l) / 2;
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    }
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    for (int i = 0; i < m; ++i) {
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        if (ans1[i] && ans2[i]) {
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            ll d = gcd(ans1[i], ans2[i]);
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            cout << ans1[i] / d << '/' << ans2[i] / d << '\n';
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        } else {
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            cout << 0 << '/' << 1 << '\n';
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        }
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    }
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}
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int main() {
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    cin.tie(nullptr)->sync_with_stdio(false);
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    solve();
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}