#include <bits/stdc++.h>
using namespace std;

#define For(i, a, b) for(int i = (a); i < (b); i++)
#define rep(i, n) For(i, 0, n)
#define rFor(i, a, b) for(int i = (a); i >= (b); i--)
#define ALL(v) (v).begin(), (v).end()
#define rALL(v) (v).rbegin(), (v).rend()
#define SZ(v) ((int)(v).size())

using lint = long long;
using ld = long double;

const int INF = 2000000000;
const lint LINF = 1000000000000000000;
// 真上から反時計回り
const int di[] = {-1, 0, 1, 0};
const int dj[] = {0, -1, 0, 1};
const int di8[] = {-1, -1, 0, 1, 1, 1, 0, -1};
const int dj8[] = {0, -1, -1, -1, 0, 1, 1, 1};

struct SetupIo {
    SetupIo() {
        ios::sync_with_stdio(false); cin.tie(nullptr);
        cout << fixed << setprecision(15);
        cerr << fixed << setprecision(15);
    }
} setupio;

namespace tatsumr {

template <class T>
bool chmin(T &a, const T &b) {
    return a > b ? a = b, 1 : 0;
}
template <class T>
bool chmax(T &a, const T &b) {
    return a < b ? a = b, 1 : 0; 
}
template <class T>
T mypow(T a, T b) {
    T res = 1;
    while (b) {
        if (b & 1) { res *= a; }
        a *= a; b >>= 1;
    }
    return res;
}
template <class T>
T modpow(T a, T b, T mod) {
    T res = 1;
    while (b) {
        if (b & 1) { res = (res * a) % mod; }
        a = (a * a) % mod; b >>= 1;
    }
    return res;
}

} // namespace tatsumr

using namespace tatsumr;

namespace fastprime {

template <class T>
T modpow(T a, T b, T mod) {
    T cur = a % mod, res = 1 % mod;
    while (b) {
        if (b & 1) {
            res = (res * cur) % mod;
        }
        cur = (cur * cur) % mod;
        b >>= 1;
    }
    return res;
}

bool MillerRabin(long long n) {
    if (n <= 1) {
        return false;
    }
    if (n == 2 || n == 7 || n == 61) {
        return true;
    }
    if (n % 2 == 0) {
        return false;
    }
    
    vector<long long> A;
    if (n < 4759123141) {
        A = {2, 7, 61};
    } else {
        A = {2, 325, 9375, 28178, 450775, 9780504, 1795265022};
    }
    long long s = 0, d = n - 1;
    while (d % 2 == 0) {
        s++;
        d >>= 1;
    }
    for (auto a : A) {
        if (a % n == 0) {
            return true;
        }
        long long x = modpow<__int128_t>(a, d, n);
        if (x == 1) {
            continue;
        }
        bool ok = false;
        for (int i = 0; i < s; i++) {
            if (x == n - 1) {
                ok = true;
                break;
            }
            x = (__int128_t)x * x % n;
        }
        if (!ok) {
            return false;
        }
    }
    return true;
}

long long gcd(long long x, long long y) {
    if (y == 0) {
        return x;
    }
    return gcd(y, x % y);
}

unsigned int xorshift() {
    static unsigned int x = 123456789, y = 362436069, z = 521288629, w = 88675123;
    unsigned int t = (x ^ (x << 11));
    x = y;
    y = z;
    z = w;
    return (w = (w ^ (w >> 19)) ^ (t ^ (t >> 8)));
}

long long Pollard(long long n) {
    if (n % 2 == 0) {
        return 2LL;
    }
    if (MillerRabin(n)) {
        return n;
    }
    
    long long i = 0;
    while (true) {
        i++;
        long long r = xorshift();
        auto f = [&](long long x) {
            return (__int128_t(x) * x + r) % n;
        };
        long long x = i, y = f(x);
        while (true) {
            long long p = gcd(abs(y - x + n), n);
            if (p == 0 || p == n) {
                break;
            }
            if (p != 1) {
                return p;
            }
            x = f(x);
            y = f(f(y));
        }
    }
}

vector<long long> prime_factorize(long long n) {
    if (n == 1) {
        return {};
    }
    long long p = Pollard(n);
    if (p == n) {
        return {p};
    }
    vector<long long> l = prime_factorize(p);
    vector<long long> r = prime_factorize(n / p);
    for (auto x : r) {
        l.emplace_back(x);
    }
    sort(l.begin(), l.end());
    return l;
}

vector<long long> divisors(long long n) {
    if (n == 1) {
        return {1LL};
    }
    auto divisor_dfs = [&](auto divisor_dfs, vector<pair<long long, long long>> &p, long long t, int cur, vector<long long> &res) -> void {
        if (cur == p.size()) {
            res.emplace_back(t);
            return;
        }
        divisor_dfs(divisor_dfs, p, t, cur + 1, res);
        for (int i = 0; i < p[cur].second; i++) {
            t *= p[cur].first;
            divisor_dfs(divisor_dfs, p, t, cur + 1, res);
        }
    };
    
    vector<long long> res, pf = prime_factorize(n);
    
    vector<pair<long long, long long>> p;
    long long cnt = 1, now = pf[0];
    for (int i = 1; i < (int)pf.size(); i++) {
        if (pf[i] == now) {
            cnt++;
        } else {
            p.emplace_back(now, cnt);
            now = pf[i];
            cnt = 1;
        }
    }
    p.emplace_back(now, cnt);
    
    divisor_dfs(divisor_dfs, p, 1, 0, res);
    sort(res.begin(), res.end());
    return res;
}

} // namespace fastprime

using namespace fastprime;

// y*(y+1) = x なる y, なければ -1
lint f(lint x) {
    lint sq = sqrt(x);
    for (lint y = sq - 2; y <= sq + 2; y++) {
        if (y >= 0 && y * (y + 1) == x) {
            return y;
        }
    }
    return -1;
}

int main() {
    lint N;
    cin >> N;
    lint M = N * 4;
    vector<pair<lint, lint>> ans;
    auto ds = divisors(M);
    for (lint a : ds) {
        lint b = M / a;
        if (a > b) {
            break;
        }
        if ((a % 2) != (b % 2)) {
            continue;
        }
        lint x = (b + a) / 2LL; // R(R+1)
        lint y = (b - a) / 2LL; // (L-1)L
        lint r = f(x), l = f(y) + 1;
        if (l >= 1 && r >= 1) {
            ans.emplace_back(l, r);
        }
    }
    sort(ALL(ans));
    ans.erase(unique(ALL(ans)), ans.end());
    cout << SZ(ans) << "\n";
    for (auto [l, r] : ans) {
        cout << l << " " << r << "\n";
    }
}