Language: C++

// >>> TEMPLATES
#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < int(n); i++)
#define rep1(i,n) for (int i = 1; i <= int(n); i++)
#define repR(i,n) for (int i = int(n)-1; i >= 0; i--)
#define rep1R(i,n) for (int i = int(n); i >= 1; i--)
#define loop(i,a,B) for (int i = a; i B; i++)
#define loopR(i,a,B) for (int i = a; i B; i--)
#define all(x) (x).begin(), (x).end()
#define allR(x) (x).rbegin(), (x).rend()
#define eb emplace_back
#define mp make_pair
#define fst first
#define snd second
#ifdef LOCAL
#define dump(...) cerr << "[" << __LINE__ << ":" << __FUNCTION__ << "] ", dump_impl(#__VA_ARGS__, __VA_ARGS__)
#define say(x) cerr << "[" << __LINE__ << ":" << __FUNCTION__ << "] " << x << endl;
#define debug if (1)
void dump_impl(const char*) { cerr << endl; }
template <class T, class... U> void dump_impl(const char *s, T const& x, U const& ...y) { const char *o = "({[", *e = "]})"; for (int i = 0; *s != '\0'; cerr << *s++) { if (count(o,o+3,*s)) i++; if (count(e,e+3,*s)) i--; if (!i && *s == ',') break; } cerr << " = " << x; if (*s == ',') cerr << ", ", s++; dump_impl(s, y...); }
#else
#define dump(...)
#define say(x)
#define debug if (0)
#endif
using ll = long long;
using ld = long double;
#define int ll
#define double ld
template <class T> using pque_max = priority_queue<T>;
template <class T> using pque_min = priority_queue<T, vector<T>, greater<T> >;
template <class T, class = typename T::iterator, class = typename enable_if<!is_same<T, string>::value>::type>
ostream& operator<<(ostream& os, T const& v) { os << "{"; for (auto const& x : v) os << " " << x; return os << " }"; }
template <class T> istream& operator>>(istream& is, vector<T>& v) { for (auto& x : v) is >> x; return is; }
template <class T, class S> ostream& operator<<(ostream& os, pair<T,S> const& p) { return os << "(" << p.first << ", " << p.second << ")"; }
template <class T, class S> istream& operator>>(istream& is, pair<T,S>& p) { return is >> p.first >> p.second; }
template <size_t i, class T> typename enable_if<i >= tuple_size<T>::value>::type output_tuple(ostream&, T const&) { }
template <size_t i = 0, class T> typename enable_if<i < tuple_size<T>::value>::type
output_tuple(ostream& os, T const& t) { os << (i ? " " : "") << get<i>(t); output_tuple<i+1,T>(os,t); }
template <class... T> ostream& operator<<(ostream& os, tuple<T...> const& t) { return output_tuple(os,t), os; }
struct IOSetup { IOSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } } iosetup;
template <class T, size_t d> struct vec_impl {
    using type = vector<typename vec_impl<T,d-1>::type>;
    template <class... U> static type make_v(size_t n, U&&... x) { return type(n, vec_impl<T,d-1>::make_v(forward<U>(x)...)); }
};
template <class T> struct vec_impl<T,0> { using type = T; static type make_v(T const& x = {}) { return x; } };
template <class T, size_t d = 1> using vec = typename vec_impl<T,d>::type;
template <class T, size_t d = 1, class... Args> auto make_v(Args&&... args) { return vec_impl<T,d>::make_v(forward<Args>(args)...); }
template <class T> void quit(T const& x) { cout << x << endl; exit(0); }
template <class T> constexpr bool chmin(T& x, T const& y) { if (x > y) { x = y; return true; } return false; }
template <class T> constexpr bool chmax(T& x, T const& y) { if (x < y) { x = y; return true; } return false; }
template <class It> constexpr auto sumof(It b, It e) { return accumulate(b,e,typename iterator_traits<It>::value_type{}); }
template <class T> int sz(T const& x) { return x.size(); }
const ll INF = (1LL<<62)-1; // ~ 4.6e18
// <<<
// >>> runtime modint
using ll = long long;
class runtime_modint {
    using M = runtime_modint;
    ll x;
public:
    static ll& mod() { static int mod = 0; return mod; }
    runtime_modint(ll x = 0) {
        assert(mod() > 0); this->x = ((x%=mod()) < 0 ? x+mod() : x);
    }
    ll val() const { return x; }
    bool operator==(M r) const { return x == r.x; }
    bool operator!=(M r) const { return x != r.x; }
    M operator+() const { return *this; }
    M operator-() const { return {mod()-x}; }
    M& operator+=(M r) { if ((x += r.x) >= mod()) x -= mod(); return *this; }
    M& operator-=(M r) { if ((x += mod()-r.x) >= mod()) x -= mod(); return *this; }
    M& operator*=(M r) { (x *= r.x) %= mod(); return *this; }
    M operator+(M r) const { return M(*this) += r; }
    M operator-(M r) const { return M(*this) -= r; }
    M operator*(M r) const { return M(*this) *= r; }
    M& operator/=(M r) { return *this *= r.inv(); }
    M operator/(M r) const { return *this * r.inv(); }
    M pow(ll n) const {
        if (n < 0) return inv().pow(-n);
        M v = *this, r = 1;
        for (; n > 0; n >>= 1, v *= v) if (n&1) r *= v;
        return r;
    }
    M inv() const {
        assert(x != 0);
        ll t = 1, v = x, q, r;
        while (v != 1) {
            q = mod() / v; r = mod() % v;
            if (r * 2 < v) {
                t *= -q; t %= mod(); v = r;
            } else {
                t *= q + 1; t %= mod(); v -= r;
            }
        }
        return t;
    }
    static int gen() { // assume mod():prime
        if (mod() == 2) return 1;
        vector<int> ps;
        int n = mod()-1;
        for (int i = 2; i*i <= n; ++i) {
            if (n % i) continue;
            ps.push_back(i);
            do n /= i; while (n % i == 0);
        }
        if (n > 1) ps.push_back(n);
        n = mod()-1;
        auto check = [&](M g) {
            for (int p : ps) if (g.pow(n/p) == 1) return false;
            return true;
        };
        for (int g = 2; g <= n; ++g) if (check(g)) return g;
        return -1;
    }
};
ostream& operator<<(ostream& os, runtime_modint r) { return os << r.val(); }
istream& operator>>(istream& is, runtime_modint &r) { ll x; is >> x; r = x; return is; }

using mint = runtime_modint;
// <<<
// >>> matrix
template <class T>
struct Matrix {
    int n,m;
    vector<vector<T> > a;
    Matrix() {}
    Matrix(int n, int m) : n(n), m(m), a(n) {
        assert(n > 0 && m > 0);
        rep (i,n) a[i].resize(m);
    }
    vector<T> const& operator[](int i) const {
        assert(0 <= i && i < n);
        return a[i];
    }
    vector<T> & operator[](int i) {
        assert(0 <= i && i < n);
        return a[i];
    }
    Matrix& operator+=(Matrix const& x) {
        assert(n == x.n && m == x.m);
        rep (i,n) rep (j,m) a[i][j] += x[i][j];
        return *this;
    }
    Matrix& operator-=(Matrix const& x) {
        assert(n == x.n && m == x.m);
        rep (i,n) rep (j,m) a[i][j] -= x[i][j];
        return *this;
    }
    Matrix operator+(Matrix const& x) const { return Matrix(*this) += x; }
    Matrix operator-(Matrix const& x) const { return Matrix(*this) -= x; }
    Matrix operator*(Matrix const& x) const {
        assert(m == x.n);
        Matrix ret(n,x.m);
        rep (i,n) rep (j,m) rep (k,x.m) ret[i][k] += a[i][j] * x[j][k];
        return ret;
    }
    Matrix& operator*=(Matrix const& x) {
        auto res = (*this)*x;
        swap(a, res.a);
        return *this;
    }
	Matrix operator+() const { return *this; }
	Matrix operator-() const {
		Matrix x = *this;
        rep (i,n) rep (j,m) x[i][j] = -x[i][j];
		return x;
	}
    Matrix& operator*=(T const& c) {
        rep (i,n) rep (j,m) a[i][j] *= c;
        return *this;
    }
    Matrix operator*(T const& c) const { return Matrix(*this) *= c; }
    friend Matrix operator*(T const& c, Matrix const& x) {
        Matrix ret = x;
        rep (i,x.n) rep (j,x.m) ret[i][j] = c*x[i][j];
        return ret;
    }
    // Matrix& operator/=(Matrix const& x, T const& c) {
    //     rep (i,n) rep (j,m) a[i][j] /= c;
    //     return *this;
    // }
    // Matrix operator/(T const& c) const {
    //     return Matrix(*this) /= c;
    // }
    static Matrix identity(int n) {
        Matrix ret(n,n);
        rep (i,n) ret[i][i] = 1;
        return ret;
    }
    Matrix pow(ll k) const {
        assert(n == m); assert(k >= 0);
        Matrix v = *this, r = Matrix::identity(n);
        for (; k > 0; k >>= 1, v *= v) if (k&1) r *= v;
        return r;
    }
};
template <class T>
ostream& operator<<(ostream& os, Matrix<T> const& x) {
    rep (i,x.n) {
        os << "\n";
        rep (j,x.m) os << x[i][j] << " ";
    }
    return os << "\n";
}
// <<<

mint f(mint x, int n) {
    if (n == 0) return 0;
    Matrix<mint> m(2,2);
    mint init[2][2] = {
        { x, 1 },
        { 0, 1 }
    };
    rep (i,2) rep (j,2) m[i][j] = init[i][j];
    m = m.pow(n);
    return m[0][1];
}

mint g(mint x, int n) {
    if (n == 0) return 0;
    Matrix<mint> m(3,3);
    mint init[3][3] = {
        { x, 1, 0 },
        { 0, 1, -1 },
        { 0, 0, 1 }
    };
    rep (i,3) rep (j,3) m[i][j] = init[i][j];
    m = m.pow(n-1);
    return m[0][0]*(n-1) + m[0][1]*(n-2) + m[0][2];
}

int32_t main() {
    int n,a,b,m; cin >> n >> a >> b >> m;
    mint::mod() = m;

    const int N = 18;
    vector<int> l(N+1),r(N+1);
    l[1] = 0; r[N] = n;
    rep1 (i,N-1) {
        int lw = -1, up = n;
        while (lw+1 < up) {
            int mid = (lw+up)/2;
            (sz(to_string(a+b*mid)) >= i+1 ? up : lw) = mid;
        }
        r[i] = l[i+1] = up;
    }
    // rep1 (i,N) dump(i,l[i],r[i]);

    vector<mint> v(N+1);
    rep1 (d,N) {
        v[d] = f(mint(10).pow(d), r[d]-l[d]) * (a+b*(r[d]-1))
            + g(mint(10).pow(d), r[d]-l[d]) * (-b);
    }
    vector<int> s(N+2);
    rep1R (i,N) s[i] = s[i+1] + i*(r[i]-l[i]);
    // rep1 (i,N) if (s[i] < 0) quit(-1);
    // if (N*(r[N]-l[N]) < 0) quit(-1);
    if (s[N+1] >= 0 && N*(r[N]-l[N])s[N+1] >= 0 && N*(r[N]-l[N]) < 0) quit(-1);
    if (s[N] < 0) assert(0);

    mint sum = 0;
    rep1 (i,N) sum += v[i]*mint(10).pow(s[i+1]);
    cout << sum << endl;

    //
    dump(l);
    dump(r);
    dump(v);
    dump(s);
    // dump(f(100,6));
    // dump(g(100,6));
}


Compiler output:
a.cc: In function 'int32_t main()':
a.cc:260:37: error: expected ')' before 's'
  260 |     if (s[N+1] >= 0 && N*(r[N]-l[N])s[N+1] >= 0 && N*(r[N]-l[N]) < 0) quit(-1);
      |        ~                            ^
      |                                     )