#include<bits/stdc++.h>
using namespace std;
char q[17] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
string o;

bool huiwen(string m) {
	for (int i = 0; i < m.length() / 2; i++) {
		if (m[i] != m[m.length() - 1 - i]) {
			return 0;
		}
	}
	return 1;
}

string swaps(string q) {
	for (int i = 0; i < q.length() / 2; i++) {
		swap(q[i], q[q.length() - 1 - i]);
	}
	return q;
}

string add(string a, string b, int k) {
	int numa[105], numb[105], numc[105];
	int len = a.length(), lenc = 1;
	string ans;
	for (int i = 0; i < len; i++) {
		if (isdigit(a[i])) numa[len - i] = a[i] - '0';
		else numa[len - i] = a[i] - 'A' + 10;
		if (isdigit(b[i])) numb[len - i] = b[i] - '0';
		else numb[len - i] = b[i] - 'A' + 10;
	}
	int x = 0;
	while (lenc <= len) {
		numc[lenc] = numa[lenc] + numb[lenc] + x;
		x = numc[lenc] / k;
		numc[lenc] %= k;
		lenc++;
	}
	numc[lenc] = x;
	while (numc[lenc] == 0) lenc--;
	for (int i = lenc; i >= 1; i--) ans += q[numc[i]];
	return ans;
}

int main() {
	int jw;
	cin >> jw;
	cin >> o;
	for (int i = 1; i <= 31; i++) {
		if (huiwen(o)) {
			cout << i - 1;
			return 0;
		}
		if (i == 31) {
			cout << "Impossible!";
			return 0;
		}
		o = add(swaps(o), o, jw);
	}
	return 0;
}