#!/usr/bin/env python3
def solve(b, d):
    k = 1
    d -= 1
    while d - k * (pow(b, k) - pow(b, k - 1)) >= 0:
        d -=  k * (pow(b, k) - pow(b, k - 1))
        k += 1
    d1 = (k - 1 - d) % k
    for _ in range(d1):
        d //= b
    return (d1 == k - 1) + (d // k) % b

if __name__ == '__main__':
    b = int(input())
    d = 0
    for c in input():
        d = b * d + int(c)
    print(solve(b, d))