#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
using namespace std;
typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
const ll mod = 1000000007;
typedef long double ld;
typedef complex<ld> Point;
const ll INF = mod * mod;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
const ld eps = 1e-6;
const ld pi = acos(-1.0);
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;

bool isnum(char t) {
	if ('0' <= t && t <= '9')return true;
	else return false;
}
bool isalf(char t) {
	if ('A' <= t && t <= 'Z')return true;
	else return false;
}

string s; int c;

void solve() {
	c++;
	stack<int> num;

	stack<string> st;

	int n = s.length();
	string cur;
	rep(i, n) {
		//cout << i << " ";
		//cout << cur << endl;
		if (isnum(s[i])) {
			int le = i;
			while (isnum(s[i + 1]))i++;
			int len = i - le + 1;
			int z = stoi(s.substr(le, len));
			i++;
			if (isalf(s[i])) {
				//add
				rep(j, z)cur.push_back(s[i]);
				if (cur.size() >= c) {
					cout << cur[c - 1] << endl; return;
				}
			}
			else {
				num.push(z); st.push(cur);
				c -= cur.size();
				cur.clear();
			}
		}
		else if (isalf(s[i])) {
			cur.push_back(s[i]);
			if (cur.size() >= c) {
				cout << cur[c - 1] << endl; return;
			}
		}
		else if(s[i]==')'){
			if (st.empty()) {
				cout << 0 << endl; return;
			}
			int u = num.top(); num.pop();
			string ori = cur;
			rep(j, u - 1) {
				cur += ori;
				if (cur.size() >= c) {
					cout << cur[c - 1] << endl; return;
				}
			}
			string past = st.top(); st.pop();
			c += past.size();
			cur = past + cur;
		}
	}
	cout << 0 << endl; return;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	while (cin >> s >> c) {
		if (s == "0")break;
		solve();
	}
	//stop
	return 0;
}
