Buggy python submission (verdict: Runtime Error):
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300003):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
        n_c=min(n_a,n_b)
        n_a, n_b=n_a-min(n_a,n_b), n_b-min(n_a,n_b)
        count=0
        while n_a + n_b + n_c <=n and n_c>=0 and n_b>=0 and n_a>=0:
#            ans+=com(n, n_c, mod) * com(n-n_c, n_b, mod) * com(n-n_c-n_b, n_a, mod) %mod
            if count==0:
                aaa0=com(n, n_c, mod) * com(n-n_c, n_b, mod) * com(n-n_c-n_b, n_a, mod) 
                ans+=aaa0
                count+=1
            n_b+=1
            n_a+=1
            aaa0 = aaa0 * n_c / ( (n_a) * (n_b) * (n-n_c-n_b-n_a) )
            n_c-=1
            if count!=0:
                ans+=aaa

print(ans%mod)

Fixed submission:
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300003):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
        if  max(n_a, n_b) <=n:
            ans+=com(n, n_a, mod) * com(n, n_b, mod)  %mod

print(ans%mod)

Buggy python submission (verdict: Time Limit Exceeded):
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300003):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
        n_c=min(n_a,n_b)
        n_a, n_b=n_a-min(n_a,n_b), n_b-min(n_a,n_b)
        count=0
        while n_a + n_b + n_c <=n and n_c>=0 and n_b>=0 and n_a>=0:
            ans+=com(n, n_c, mod) * com(n-n_c, n_b, mod) * com(n-n_c-n_b, n_a, mod) %mod

            n_c-=1
            n_b+=1
            n_a+=1

print(ans%mod)

Fixed submission:
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300003):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
        if  max(n_a, n_b) <=n:
            ans+=com(n, n_a, mod) * com(n, n_b, mod)  %mod

print(ans%mod)

Buggy python submission (verdict: Time Limit Exceeded):
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300003):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
        n_c=min(n_a,n_b)
        n_a, n_b=n_a-min(n_a,n_b), n_b-min(n_a,n_b)
        count=0
        while n_a + n_b + n_c <=n and n_c>=0 and n_b>=0 and n_a>=0:
            ans+=com(n, n_c, mod) * com(n-n_c, n_b, mod) * com(n-n_c-n_b, n_a, mod)

            n_c-=1
            n_b+=1
            n_a+=1

print(ans%mod)

Fixed submission:
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300003):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
        if  max(n_a, n_b) <=n:
            ans+=com(n, n_a, mod) * com(n, n_b, mod)  %mod

print(ans%mod)

Buggy python submission (verdict: Time Limit Exceeded):
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300003):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

#test=2*3*com(4, 2, mod) + com(4,3,mod)
#print(test)

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
        
        n_c=min(n_a,n_b)
        n_a, n_b=n_a-min(n_a,n_b), n_b-min(n_a,n_b)

        while n_a + n_b + n_c <=n and n_c>=0 and n_b>=0 and n_a>=0:
            ans+=com(n, n_c, mod) * com(n-n_c, n_b, mod) * com(n-n_c-n_b, n_a, mod)
            n_c-=1
            n_b+=1
            n_a+=1

print(ans%mod)

Fixed submission:
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300003):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
        if  max(n_a, n_b) <=n:
            ans+=com(n, n_a, mod) * com(n, n_b, mod)  %mod

print(ans%mod)

Buggy python submission (verdict: Runtime Error):
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300000):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

#test=2*3*com(4, 2, mod) + com(4,3,mod)
#print(test)

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
#        print(n_a, n_b)
        
        n_c=min(n_a,n_b)
        n_a, n_b=n_a-min(n_a,n_b), n_b-min(n_a,n_b)
#        print(n_a, n_b, n_c)

        while n_a + n_b + n_c <=n and n_c>=0 and n_b>=0 and n_a>=0:
            ans+=com(n, n_c, mod) * com(n-n_c, n_b, mod) * com(n-n_c-n_b, n_a, mod)
            n_c-=1
            n_b+=1
            n_a+=1
print(ans%mod)

Fixed submission:
n,a,b,k=[int(i) for i in input().split()]
c=a+b
mod=998244353
ans=0

g1 = [1, 1]  # 元テーブル
g2 = [1, 1]  #逆元テーブル
inverse = [0, 1]  #逆元テーブル計算用テーブル

for i in range(2,300003):
    g1.append( ( g1[-1] * i ) % mod )
    inverse.append( ( -inverse[mod % i] * (mod//i) ) % mod )
    g2.append( (g2[-1] * inverse[-1]) % mod )

#以下のcom関数を用いて組み合わせを計算
def com(n, r, mod):
    if ( r<0 or r>n ):
        return 0
    r = min(r, n-r)
    return g1[n] * g2[r] * g2[n-r] % mod

for i in range(n+1):
    if (k-b*i)%a==0 and k-b*i>=0:
        n_a=(k-b*i)//a
        n_b=i
        if  max(n_a, n_b) <=n:
            ans+=com(n, n_a, mod) * com(n, n_b, mod)  %mod

print(ans%mod)