#include <bits/stdc++.h>
                            #include<iostream>
                            #include<cstdio>
                            #include<vector>
                            #include<queue>
                            #include<map>
                            #include<cstring>
                            #include<string>
                            #include <math.h>
                            #include<algorithm>
                        //    #include <boost/multiprecision/cpp_int.hpp>
                            #include<functional>
                     #define int long long
                            #define inf  1000000007
                            #define pa pair<int,int>
                            #define ll long long
                            #define pal pair<double,pa>
                            #define ppa pair<pa,int>
                            #define ppap pair<int,pa>
                            #define ssa pair<string,int>
                            #define  mp make_pair
                            #define  pb push_back
                            #define EPS (1e-10)
                            #define equals(a,b) (fabs((a)-(b))<EPS)
                     
                            using namespace std;
                     //priority_queue<int, vector<int>, greater<int> > que;
                            class Point{
                            	public:
                            	double x,y;
                            	Point(double x=0,double y=0):x(x),y(y) {}
                            	Point operator + (Point p) {return Point(x+p.x,y+p.y);}
                            	Point operator - (Point p) {return Point(x-p.x,y-p.y);}
                            	Point operator * (double a) {return Point(x*a,y*a);}
                            	Point operator / (double a) {return Point(x/a,y/a);}
                            	double absv() {return sqrt(norm());}
                            	double norm() {return x*x+y*y;}
                            	bool operator < (const Point &p) const{
                            		return x != p.x ? x<p.x: y<p.y;
                            	}
                            	bool operator == (const Point &p) const{
                            		return fabs(x-p.x)<EPS && fabs(y-p.y)<EPS;
                            	}
                            };
                            typedef Point Vector;
                     
                            struct Segment{
                            Point p1,p2;
                            };
                     
                        double hen(Vector a){
                        if(fabs(a.x)<EPS && a.y>0) return acos(0);
                        else if(fabs(a.x)<EPS && a.y<0) return 3*acos(0);
                        else if(fabs(a.y)<EPS && a.x<0) return 2*acos(0);
                        else if(fabs(a.y)<EPS && a.x>0) return 0.0;
                        else if(a.y>0) return acos(a.x/a.absv());
                        else return 2*acos(0)+acos(-a.x/a.absv());
                     
                        }
                     
                string itos( int i ) {
                ostringstream s ;
                s << i ;
                return s.str() ;
                }
                 
                int gcd(int v,int b){
                	if(v>b) return gcd(b,v);
                	if(v==b) return b;
                	if(b%v==0) return v;
                	return gcd(v,b%v);
                }
                            double dot(Vector a,Vector b){
                            	return a.x*b.x+a.y*b.y;
                            }
                            double cross(Vector a,Vector b){
                            	return a.x*b.y-a.y*b.x;
                            }
                        
                double distans(double x1,double y1,double x2,double y2){
                	double rr=(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);
                	return sqrt(rr);
                	
                }
                /*}
int pr[100010];
//int inv[100010];
 
int beki(int wa,int rr){
	if(rr==0) return 1ll;
	if(rr==1) return wa;
	if(rr%2==1) return (beki(wa,rr-1)*wa)%inf;
	int zx=beki(wa,rr/2);
	return (zx*zx)%inf;
}
  
void gya(){
	pr[0]=1;
	for(int i=1;i<100010;i++){
		pr[i]=(pr[i-1]*i)%inf;
	}
	for(int i=0;i<100010;i++) inv[i]=beki(pr[i],inf-2);
	
}

*/

                         //----------------kokomade tenpure------------

int a[200020]={0};
string s,t,tt;
vector<int> G[100000];
int b[200020];
char c[200020];
int kosuu=0;
int kazu[200020];
int nu(int i){
	int r=0;
	for(int j=i;j<=s.length();j++){
		if(s[j]<='9' &&s[j]>='0'){
		r*=10;
		r += s[j]-'0';
		}
		else break;
	}
	return r;
}

void dfs(int i,int j,int oya){
	if(i>j) return;
//	cout<<s.substr(i,j-i+1)<<endl;
	kosuu++;
	int r=kosuu;
//	cout<<i<<" "<<j<<" "<<oya<<endl;
//	cout<<oya<<" "<<r<<endl;
	if(s[i]>='A'&&s[i]<='Z'){
		G[oya].pb(r);
		
		b[r]=1;
		c[r]=s[i];
//		cout<<"r="<<r<<endl;
		dfs(i+1,j,oya);
	}
	else{
		G[oya].pb(r);
		b[r]=nu(i);
		if(s[a[i]]=='('){
		dfs(a[a[i]]+1,j,oya);
		dfs(a[i]+1,a[a[i]]-1,r);
		}
		else{
			dfs(a[i]+1,j,oya);
			c[r]=s[a[i]];
//		cout<<"r="<<r<<endl;
		}
	}
}


int kei(int u){
	int r=0;
	if(G[u].size()==0){
		kazu[u]=1;
		return 1;
	}
	for(int j=0;j<G[u].size();j++){
		r += b[G[u][j]]*kei(G[u][j]);
		r=min(r,10000000ll);
	}
	kazu[u]=r;
	//cout<<"kosuu"<<u<<" "<<r<<endl;
	return r;
}
char ans;

void ch(int oya,int r){
//	cout<<oya<<" "<<kazu[oya]<<" "<<r<<endl;
	int u=0;
	if(G[oya].size()==0){
		ans=c[oya];
		//cout<<c[oya]<<endl;
		return;
	} 
	while(1){
		
		if(kazu[G[oya][u]]*b[G[oya][u]]<r) r-=kazu[G[oya][u]]*b[G[oya][u]];
		else{
			r %= kazu[G[oya][u]];
			if(r==0) r=kazu[G[oya][u]];
			ch(G[oya][u],r);
			break;
		}
		u++;
	}
}

signed main(){

	
	while(1){
		//string s;
		int r;
		int na,nb;
	cin>>s>>r;
		if(s=="0" && r==0) return 0;
	//	s="1("+s+")";
		for(int i=0;i<100000;i++){
			G[i].clear();
			kazu[i]=0;
		}
		int i;
		stack<int> st;
		for(int i=0;i<s.length();i++){
			if(s[i]=='('){
				st.push(i);
			}
			if(s[i]==')'){
			int 	y=st.top();
				st.pop();
				a[y]=i;
			}
			if(s[i]>='0' && s[i]<='9'){
				int g=i+1;
				while(s[g]>='0' && s[g]<='9')g++;
				a[i]=g;
			}
		}
		
		kosuu=0;
	//	for(int i=0;i<s.length();i++) cout<<a[i]<<" ";
	//	cout<<endl;
		dfs(0,s.length()-1,0);
//	cout<<	kei(0)<<endl;
		kei(0);
		if(kazu[0]<=r) cout<<0<<endl;
		else{
		ch(0,r+1);
		cout<<ans<<endl;
		}
	}
	
		
	return 0;
}

Measured memory_bytes: 6356