import javax.swing.JOptionPane;

public class Main {
	public static void main(String args[]){
		String theirInput = JOptionPane.showInputDialog(null, "Enter the number to convert, followed by the base it's in, followed by the base to convert to");
		char theirInputArr[] = theirInput.toCharArray();
		StringBuilder startNumB = new StringBuilder();
		StringBuilder baseNumB = new StringBuilder();
		StringBuilder nextBaseNumB = new StringBuilder();
		for(int i = 0, word = 0; i<theirInputArr.length; i++){
			if(theirInputArr[i] != ' ' && word == 0){
				startNumB.append(theirInputArr[i]);
			}else if(theirInputArr[i] != ' ' && word == 1){
				baseNumB.append(theirInputArr[i]);
			}else if(theirInputArr[i] != ' ' && word == 2){
				nextBaseNumB.append(theirInputArr[i]);
			}else if(theirInputArr[i] == ' '){
				word++;
			}
		}
		String startNum = startNumB.toString();
		int baseNum = Integer.parseInt(baseNumB.toString());
		int nextBaseNum = Integer.parseInt(nextBaseNumB.toString());
		if(baseNum > 36 || nextBaseNum > 36){
			JOptionPane.showMessageDialog(null, "Bases cannot be larger than 36");
		}else{
			char fullArr[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
			char firBaseArr[] = new char[baseNum];
			char nextBaseArr[] = new char[nextBaseNum];
			for(int i = 0; i<baseNum; i++){
				firBaseArr[i] = fullArr[i];
			}
			for(int i = 0; i<nextBaseNum; i++){
				nextBaseArr[i] = fullArr[i];
			}
			char checkSameArr[] = new char[startNum.length()];
			char actualNumArr[] = startNum.toCharArray();
			int decVal = 0;
			for(int i = 0, i2 = 0;;){
				checkSameArr[i] = firBaseArr[i2];
				if(!(checkSameArr[i] == actualNumArr[i])){
					decVal++;
					i2++;
				}else{
					if(i<checkSameArr.length-1){
						decVal++;
						i++;
					}else{
						break;
					}
					i2 = 0;
				}
			}
			char newNum[] = new char[decVal];
			boolean check = false;
			for(int i = 0, place = 0, subVal = 0; i<decVal; i++){
				place = 0;
				check = false;
				if(!(i-subVal >= nextBaseArr.length)){
					newNum[place] = nextBaseArr[i-subVal];
				}else{
					for(int findPlace = 0;;findPlace++){
						if(nextBaseArr[findPlace] == newNum[place] && findPlace<nextBaseArr.length-1){
							newNum[place++] = nextBaseArr[findPlace++];
							break;
						}else if(nextBaseArr[findPlace] == newNum[place++] && !(findPlace<nextBaseArr.length-1)){
							while(!check){
								if(place++ == nextBaseArr[nextBaseArr.length-1]){
									newNum[place++] = '0';
									newNum[place+2] = nextBaseArr[1];
									subVal += nextBaseNum;
									check = true;
								}else{
									place++;
								}
							}
							break;
						}
					}
				}
			}
			JOptionPane.showMessageDialog(null, "New number = " + newNum.toString());
		}
	}
}