# Original solution
import sys
def main():
    input = sys.stdin.readline
    N,S = list(map(int, input().split()))
    A = list(map(int, input().split()))
    MOD = 998244353

    dp = [[[0 for _ in range(3)] for _ in range(S+1)] for _ in range(N+1)]
    dp[0][0][0] = 1
    for i in range(N):
        a = A[i]
        for j in range(S+1):
            dp[i+1][j][0] = (dp[i+1][j][0] + dp[i][j][0]) % MOD
            dp[i+1][j][1] = (dp[i+1][j][1] + dp[i][j][1]) % MOD
            dp[i+1][j][2] = (dp[i+1][j][2] + dp[i][j][2]) % MOD

            if j+a > S: continue
            dp[i+1][j+a][1] = (dp[i+1][j+a][1] + dp[i][j][1] + (dp[i][j][0] * (i+1))) % MOD
            dp[i+1][j+a][2] = (dp[i+1][j+a][2] + (dp[i][j][1] * (N-i)) + (dp[i][j][0] * (i+1) * (N-i))) % MOD

    print((dp[N][S][2]))

if __name__ == '__main__':
    main()

# Optimized solution
import sys
def main():
    input = sys.stdin.readline
    N,S=list(map(int, input().split()))
    *A,=list(map(int, input().split()))

    ans = Mint()
    q = [Mint() for _ in range(S+1)]
    for a in A:
        q[0] += 1
        for i in range(S-a,-1,-1): q[i+a] += q[i]
        ans += q[S]
    print(ans)

MOD = 998244353
class Mint:
    def __init__(self, value=0):
        self.value = value % MOD
        if self.value < 0: self.value += MOD

    @staticmethod
    def get_value(x): return x.value if isinstance(x, Mint) else x

    def inverse(self):
        a, b = self.value, MOD
        u, v = 1, 0
        while b:
            t = a // b
            b, a = a - t * b, b
            v, u = u - t * v, v
        if u < 0: u += MOD
        return u

    def __repr__(self): return str(self.value)
    def __eq__(self, other): return self.value == other.value
    def __neg__(self): return Mint(-self.value)
    def __hash__(self): return hash(self.value)
    def __bool__(self): return self.value != 0

    def __iadd__(self, other):
        self.value += Mint.get_value(other)
        if self.value >= MOD: self.value -= MOD
        return self
    def __add__(self, other):
        new_obj = Mint(self.value)
        new_obj += other
        return new_obj
    __radd__ = __add__

    def __isub__(self, other):
        self.value -= Mint.get_value(other)
        if self.value < 0: self.value += MOD
        return self
    def __sub__(self, other):
        new_obj = Mint(self.value)
        new_obj -= other
        return new_obj
    def __rsub__(self, other):
        new_obj = Mint(Mint.get_value(other))
        new_obj -= self
        return new_obj

    def __imul__(self, other):
        self.value = self.value * Mint.get_value(other) % MOD
        return self
    def __mul__(self, other):
        new_obj = Mint(self.value)
        new_obj *= other
        return new_obj
    __rmul__ = __mul__

    def __ifloordiv__(self, other):
        other = other if isinstance(other, Mint) else Mint(other)
        self *= other.inverse()
        return self
    def __floordiv__(self, other):
        new_obj = Mint(self.value)
        new_obj //= other
        return new_obj
    def __rfloordiv__(self, other):
        new_obj = Mint(Mint.get_value(other))
        new_obj //= self
        return new_obj

if __name__ == '__main__':
    main()