import numpy as np
b = int(input()) 
def count(mid):
    tp = b ** mid
    return mid * tp - (tp - 1) // (b - 1)
n = int(input(), b)
digit = 0
l = 1
r = 100000
while l <= r:
    mid = (l + r) // 2
    cur_t = count(mid)
    if cur_t >= n:
        r = mid - 1
        digit = mid
    else:
        l = mid + 1
n -= count(digit - 1)
num = b ** (digit - 1) + ((n + digit - 1) // digit) - 1
# print(np.base_repr(num, b)[(n - 1) % digit])