#include <bits/stdc++.h>
#ifdef LOCAL
#include "./debug.cpp"
#else
#define debug(...)
#define print_line
#endif
using namespace std;
using ll = long long;

#include <iostream>

/**
 * @brief Modint
 */

template <long long MOD>
struct modint {
    long long value;
    modint(long long x = 0) {
        if (x >= 0) {
            value = x % MOD;
        } else {
            value = MOD - (-x) % MOD;
        }
    }
    modint operator-() const {
        return modint(-value);
    }
    modint operator+() const {
        return modint(*this);
    }
    modint &operator+=(const modint &other) {
        value += other.value;
        if (value >= MOD) {
            value -= MOD;
        }
        return *this;
    }
    modint &operator-=(const modint &other) {
        value += MOD - other.value;
        if (value >= MOD) {
            value -= MOD;
        }
        return *this;
    }
    modint &operator*=(const modint other) {
        value = value * other.value % MOD;
        return *this;
    }
    modint &operator/=(modint other) {
        (*this) *= other.inv();
        return *this;
    }
    modint operator+(const modint &other) const {
        return modint(*this) += other;
    }
    modint operator-(const modint &other) const {
        return modint(*this) -= other;
    }
    modint operator*(const modint &other) const {
        return modint(*this) *= other;
    }
    modint operator/(const modint &other) const {
        return modint(*this) /= other;
    }
    modint pow(long long x) const {
        modint ret(1), mul(value);
        while (x > 0) {
            if (x % 2 == 1) {
                ret *= mul;
            }
            mul *= mul;
            x /= 2;
        }
        return ret;
    }
    modint inv() const {
        return pow(MOD - 2);
    }
    bool operator==(const modint &other) const {
        return value == other.value;
    }
    bool operator!=(const modint &other) const {
        return value != other.value;
    }
    friend std::ostream &operator<<(std::ostream &os, const modint &x) {
        return os << x.value;
    }
    friend std::istream &operator>>(std::istream &is, modint &x) {
        long long v;
        is >> v;
        x = modint<MOD>(v);
        return is;
    }
};
using mod998 = modint<998244353>;
using mod107 = modint<1000000007>;
using mint = mod998;

int main() {
    int N;
    cin >> N;
    vector<int> A(N);
    for (int i = 0; i < N; i++) cin >> A[i];
    A.insert(A.begin(), 0);

    const int MAX = 1e5;
    vector<vector<mint>> dp(N + 1, vector<mint>(MAX + 1, 0));
    dp[0][0] = 1;
    for (int i = 0; i < N; i++) {
        vector<mint> sum(MAX + 2);
        for (int j = 0; j <= MAX; j++) sum[j + 1] = sum[j] + dp[i][j];
        for (int j = 0; j + A[i + 1] <= MAX; j++) {
            int upper = min({MAX - A[i], j, j - A[i] + A[i + 1]});
            upper = max(upper, -1);
            dp[i + 1][j] += sum[upper + 1];
        }
    }

    mint ans = 0;
    for (int i = 0; i <= MAX; i++) ans += dp[N][i];
    cout << ans << endl;
}