MOD = 998244353
N,M = map(int,input().split())
bl = M.bit_length()
B = [[0] * (bl + 1) for _ in range(bl+1)]
B[0][0] = 1
for i in range(1,bl+1):
    for j in range(i+1):
        B[i][j] = B[i-1][j-1] + B[i-1][j]
for i in range(bl+1):
    B[i][1] += 1

BT = [0] * (bl+1)
k = 0
for i in reversed(range(bl+1)):
    if (M >> i) & 1:
        k += 1
        for j in range(i+1):
            BT[j+k] += B[i][j+1]
ans = 1
for i in range(bl+1):
    ans += BT[i] * pow(N,i,MOD)
    ans %= MOD
print(ans)