Buggy python submission (verdict: Runtime Error):
import math
def f(b,n):
    if n<b:
        return n
    return f(b,n//b)+n%b

def main():
    n=int(input())
    s=int(input())
    if n==s:
        return n+1
    elif n <s:
        return -1
    else:
        for b in range(2,int(math.sqrt(n))+2):
            if f(b,n)==s:
                print(b)
                exit()
        for p in range(int(math.sqrt(n-s)+1),0,-1):
            b=(n-s)//p+1
            if f(b,n)==s:
                return b
    return -1

if __name__ == '__main__':
    print(main())


Fixed submission:
n = int(input())
s = int(input())

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


def solve(n,s):
  if s > n:
    return -1
  if s == n:
    return n+1
  nsq = int(n**0.5 + 1)
  for b in range(2,nsq+1):
    if f(b,n) == s:
      return b
  # 2桁で作れるかどうか
  # n = bx+y, s = x+y, x,y < b
  # n - s = (b-1)x, x < b
  m = n-s
  msq = int(m**0.5+1)
  for x in range(msq,0,-1):
    if m%x:
      continue
    b = m//x+1
    if f(b,n) == s:
      return b
  return -1
  
answer = solve(n,s)
print(answer)

Buggy python submission (verdict: Runtime Error):
import math
def f(b,n):
    if n<b:
        return n
    return f(b,n//b)+n%b

def main():
    n=int(input())
    s=int(input())
    if n==s:
        print(n+1)
        exit()
    elif n <s:
        print(-1)
        exit()
    else:
        for b in range(2,int(math.sqrt(n))+2):
            if f(b,n)==s:
                print(b)
                exit()
        for j in range(int(math.sqrt(n)+1),0,-1):
            b=(n-s)//j+1
            if f(b,n)==s:
                print(int(b))
                exit()
    print(-1)

if __name__ == '__main__':
    main()


Fixed submission:
n = int(input())
s = int(input())

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


def solve(n,s):
  if s > n:
    return -1
  if s == n:
    return n+1
  nsq = int(n**0.5 + 1)
  for b in range(2,nsq+1):
    if f(b,n) == s:
      return b
  # 2桁で作れるかどうか
  # n = bx+y, s = x+y, x,y < b
  # n - s = (b-1)x, x < b
  m = n-s
  msq = int(m**0.5+1)
  for x in range(msq,0,-1):
    if m%x:
      continue
    b = m//x+1
    if f(b,n) == s:
      return b
  return -1
  
answer = solve(n,s)
print(answer)

Buggy python submission (verdict: Runtime Error):
import math
def f(b,n):
    if n<b:
        return n
    return f(b,n//b)+n%b

def main():
    n=int(input())
    s=int(input())
    if n==s:
        print(n+1)
        exit()
    elif n <s:
        print(-1)
        exit()
    else:
        for b in range(2,int(math.sqrt(n))+2):
            if f(b,n)==s:
                print(b)
                exit()
        for j in range(int(math.sqrt(n)+1)+1,0,-1):
            b=(n-s)//j+1
            if f(b,n)==s:
                print(int(b))
                exit()
    print(-1)

if __name__ == '__main__':
    main()


Fixed submission:
n = int(input())
s = int(input())

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


def solve(n,s):
  if s > n:
    return -1
  if s == n:
    return n+1
  nsq = int(n**0.5 + 1)
  for b in range(2,nsq+1):
    if f(b,n) == s:
      return b
  # 2桁で作れるかどうか
  # n = bx+y, s = x+y, x,y < b
  # n - s = (b-1)x, x < b
  m = n-s
  msq = int(m**0.5+1)
  for x in range(msq,0,-1):
    if m%x:
      continue
    b = m//x+1
    if f(b,n) == s:
      return b
  return -1
  
answer = solve(n,s)
print(answer)