C++ :

#include<bits/stdc++.h>
using namespace std;
int main(){
	string s;
	int a,b,i,j;
	cin>>s>>a>>b;
	if(s=="0")
	{
		cout<<"("<<0<<")"<<b;
		return 0;
	}
	//转成十进制
	long long r = 0,x;
	for(i=0;i<s.size();i++)
	{
		if(s[i]>='0' && s[i]<='9') x = s[i]-'0';
		else x = s[i]-'a'+10;
		for(j=1;j<=s.size()-i-1;j++)
		{
			x = x * a;
		}
		r = r + x;
	} 
	string t ="";
	while(r!=0)
	{
		if(r%b>=10) t = char(r%b-10+'a') + t ;
		else t = char(r%b+'0') + t;
		r = r/b;
	}
	cout<<"("<<t<<")"<<b;
	return 0;
}