Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = int(input())
rtn = -1* int( -1 * (n**0.5))
def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b
if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
else:
    x = n // s
    if s - (n //(x+1))  <= x:
        x = x + 1
    if 5 < n/(x -1) - n/x :
        for b in range(n//x, n//(x-1)):
            if f(b,n) == s:
                print(b)
                exit()
        for i in range(x-1,2,-1):
            for b in range(n//i + (n//x)//(n//i), n//i + (n//x)//(n//i)  + (2*n//x - n//(x+1))//(x-i)):
                if f(b,n) == s:
                    print(b)
                    exit()
    else:
        for b in range(2,rtn+1):
            if f(b,n) == s:
                print(b)
                exit()
        for p in range(rtn,0,-1):
            if (n-s) % p == 0:
                b = (n-s)//p + 1
                if f(b,n) == s:
                    print(b)
                    exit()
    print(n-s+1)


Fixed submission:
n = int(input())
s = int(input())
rtn = -1* int( -1 * (n**0.5))
def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b
if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
else:
    for b in range(2,rtn+1):
        if f(b,n) == s:
            print(b)
            exit()
    for p in range(rtn,0,-1):
        if (n-s) % p == 0:
            b = (n-s)//p + 1
            if f(b,n) == s:
                print(b)
                exit()
    print(n-s+1)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = int(input())
rtn = -1* int( -1 * (n**0.5))
def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b
if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
elif s == 1:
    def check(n,b):
        if n == 1:
            return b
        else:
            if n % b !=0 :
                return 0
            else:
                return check(n // b,b)
    for b in range(2,rtn+1):
        r = check(n,b)
        if r:
            print(r)
            exit()
    print(n)
else:
    x = n // s
    if s - (n //(x+1))  <= x:
        x = x + 1
    if 5 < n/(x -1) - n/x :
        for b in range(n//x, n//(x-1)):
            if f(b,n) == s:
                print(b)
                exit()
        for i in range(x-1,2,-1):
            for b in range(n//i + (n//x)//(n//i), n//i + (n//x)//(n//i)  + (2*n//x - n//(x+1))//(x-i)):
                if f(b,n) == s:
                    print(b)
                    exit()
    else:
        for b in range(2,rtn+1):
            if f(b,n) == s:
                print(b)
                exit()
        for p in range(rtn,0,-1):
            if (n-s) % p == 0:
                b = (n-s)//p + 1
                if f(b,n) == s:
                    print(b)
                    exit()
    print(n-s+1)


Fixed submission:
n = int(input())
s = int(input())
rtn = -1* int( -1 * (n**0.5))
def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b
if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
else:
    for b in range(2,rtn+1):
        if f(b,n) == s:
            print(b)
            exit()
    for p in range(rtn,0,-1):
        if (n-s) % p == 0:
            b = (n-s)//p + 1
            if f(b,n) == s:
                print(b)
                exit()
    print(n-s+1)

Buggy python submission (verdict: Time Limit Exceeded):

n = int(input())
s = int(input())
rtn = int(n**0.5)+1

def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b

if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
elif s == 1:
    def check(n,b):
        if n == 1:
            return b
        else:
            if n % b !=0 :
                return 0
            else:
                return check(n // b,b)
    for b in range(2,rtn):
        r = check(n,b)
        if r:
            print(r)
            exit()
    print(n)
else:
    x = n // s
    if s - (n //(x+1))  <= x:
        x = x + 1
    if 5 < n/(x -1) - n/x :
        for b in range(n//x, n//(x-1)):
            if f(b,n) == s:
                print(b)
                exit()
        for i in range(x-1,2,-1):
            for b in range(n//i + (n//x)//(n//i), n//i + (n//x)//(n//i)  + (2*n//x - n//(x+1))//(x-i)):
                if f(b,n) == s:
                    print(b)
                    exit()
    else:
        for b in range(2,(n//3)+3):
            if f(b,n) == s:
                print(b)
                exit()
    print(n-s+1)


Fixed submission:
n = int(input())
s = int(input())
rtn = -1* int( -1 * (n**0.5))
def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b
if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
else:
    for b in range(2,rtn+1):
        if f(b,n) == s:
            print(b)
            exit()
    for p in range(rtn,0,-1):
        if (n-s) % p == 0:
            b = (n-s)//p + 1
            if f(b,n) == s:
                print(b)
                exit()
    print(n-s+1)

Buggy python submission (verdict: Runtime Error):

def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b

if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
elif s == 1:
    def check(n,b):
        if n == 1:
            return b
        else:
            if n % b !=0 :
                return 0
            else:
                return check(n // b,b)
    for b in range(2,rtn):
        r = check(n,b)
        if r:
            print(r)
            exit()
    print(n)
else:
    x = n // s
    if s - (n //(x+1))  <= x:
        x = x + 1
    if 5 < n/(x -1) - n/x :
        for b in range(n//x, n//(x-1)):
            if f(b,n) == s:
                print(b)
                exit()
        for i in range(x-1,2,-1):
            for b in range(n//i + (n//x)//(n//i), n//i + (n//x)//(n//i)  + (2*n//x - n//(x+1))//(x-i)):
                if f(b,n) == s:
                    print(b)
                    exit()
    else:
        for b in range(2,(n//3)+3):
            if f(b,n) == s:
                print(b)
                exit()
    print(n-s+1)


Fixed submission:
n = int(input())
s = int(input())
rtn = -1* int( -1 * (n**0.5))
def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b
if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
else:
    for b in range(2,rtn+1):
        if f(b,n) == s:
            print(b)
            exit()
    for p in range(rtn,0,-1):
        if (n-s) % p == 0:
            b = (n-s)//p + 1
            if f(b,n) == s:
                print(b)
                exit()
    print(n-s+1)

Buggy python submission (verdict: Runtime Error):
n = int(input())
s = int(input())

def f(b,n) :
    r = 0
    i = 1
    while n:
        j = n % b
        r += j
        n = (n-j)//b
    return r


if n < s or (n // 2)+1 < s < n :
    print("-1")
elif (n//3) + 2 < s < n//2:
    print(n-s+1)
elif s == n:
    print(n+1)
elif s == 1:
    def check(n,b):
        while 1 < n :
            if n % b != 0:
                break
            n //= b
        if n == 1:
            return b
        return 0
    for b in range(2,int(n**0.5)+2):
        r = check(n,b)
        if r:
            print(r)
            exit()
    print(n)
else:

    x = n // s
    xd = n % s
    if s - xd < x:
        x = x + 1
    if 3 < n/(x -1) - n/x :
        for b in range(n//(x-1),(n//x)+1):
            if f(b,n) == s:
                print(b)
                exit()
    for b in range(2,(n//2)+2):
        if f(b,n) == s:
            print(b)
            exit()
    print(n-s+1)


Fixed submission:
n = int(input())
s = int(input())
rtn = -1* int( -1 * (n**0.5))
def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b
if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
else:
    for b in range(2,rtn+1):
        if f(b,n) == s:
            print(b)
            exit()
    for p in range(rtn,0,-1):
        if (n-s) % p == 0:
            b = (n-s)//p + 1
            if f(b,n) == s:
                print(b)
                exit()
    print(n-s+1)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = int(input())

def f(b,n) :
    r = 0
    i = 1
    while n:
        j = n % b
        r += j
        n = (n-j)//b
    return r


if n < s or (n // 2)+1 < s < n or( n // 3 ) + 2 < s < n//2:
    print("-1")
elif s == n:
    print(n+1)
elif s == 1:
    def check(n,b):
        while 1 < n :
            if n % b != 0:
                break
            n //= b
        if n == 1:
            return b
        return 0
    for b in range(2,int(n**0.5)+2):
        r = check(n,b)
        if r:
            print(r)
            exit()
    print(n)
else:
    for b in range(2,(n//2)+2):
        if f(b,n) == s:
            print(b)
            exit()
    print(n-s+1)


Fixed submission:
n = int(input())
s = int(input())
rtn = -1* int( -1 * (n**0.5))
def f(b,n):
    if n<b:
        return n
    return f(b,n//b) + n % b
if n < s or (n // 2)+1 < s < n :
    print("-1")
elif s == n:
    print(n+1)
elif s == n//2 +1:
    if n % 2 == 1:
        print(n//2 + 1)
    else:
        print("-1")
elif (n//3) + 2 < s <= n//2:
    print(n-s+1)
else:
    for b in range(2,rtn+1):
        if f(b,n) == s:
            print(b)
            exit()
    for p in range(rtn,0,-1):
        if (n-s) % p == 0:
            b = (n-s)//p + 1
            if f(b,n) == s:
                print(b)
                exit()
    print(n-s+1)