rt

#include <bits/stdc++.h>
using namespace std;

int c[130];

bool hui(long long x){
	return (x == hui(x));
}

long long fan(long long x){
	long long sum = 0;
	while (x){
		sum = sum*10+x%10;
		x /= 10;
	}
	return sum;
}

int main(){
	c['1'] = 1;
	c['2'] = 2;
	c['3'] = 3;
	c['4'] = 4;
	c['5'] = 5;
	c['6'] = 6;
	c['7'] = 7;
	c['8'] = 8;
	c['9'] = 9;
	c['0'] = 0;
	c['a'] = 10;
	c['b'] = 11;
	c['c'] = 12;
	c['d'] = 13;
	c['e'] = 14;
	c['f'] = 15;
	int jz;
	string s;
	cin >> jz >> s;
	long long n = 0, sum = 1;
	for (int i = 0; i <= s.size(); i++){
		n += sum*c[s[i]];
		sum *= jz;
	}
	for (int i = 1; i <= 30; i++){
		if (hui(i)){
			printf("STEP=%d\n", i);
			return 0;
		}
		n += fan(n);
	}
	printf("Impossible!\n");
	return 0;
}