/*
 * shujuzuzhi2_6.cpp
 *Name?????
 *  Created on: 2011-1-13
 *      Author: ??
 */

int main() {
	int a, b, l, n = 0, i;//a?????????????b??????????l?????????????n?????????
	int y[100] = { 0 };//???????????????????
	char num[100] = { 0 };//??????????a????
	cin >> a;//????????
	cin >> num;//???????
	cin >> b;//????????
	l = strlen(num);//???????????????
	for (i = 0; i < l; i++)//????????????????
	{
		if ((num[i] >= 'a') && (num[i] <= 'z'))
			num[i] = num[i] - 87;
		else if ((num[i] >= 'A') && (num[i] <= 'Z'))
			num[i] = num[i] - 55;
		else if ((num[i] >= 48) && (num[i] <= 57))
			num[i] = num[i] - 48;
		n = n * a + num[i]; //??????n*a+num[i]???????a??num?????????10??????n??
	}
	if (n == 0)
		cout << 0;//????0???0
	else {//?10???n???b??????y???
		i = 0;
		while (n != 0) {
			y[i++] = n % b;
			n = n / b;
		}
		for (i--; i >= 0; i--) //????????y??????????
		{
			if (y[i] > 9)
				cout << (char) (y[i] + 55);
			else
				cout << y[i];
		}
	}
	cout << endl;
	return 0;
}