#include<iostream>
#include<vector>
#include <set>
#include <string>
using namespace std;

string input;
int cnt;
int target;


int solve(int pos) {
  int n = 0, endPos = INT_MAX;

  while (input[pos] >= '0' && input[pos] <= '9') {
    n = 10 * n + (input[pos] - '0');
    pos++;
  }
  if (n == 0) n = 1;
  
  

  if (input[pos] >= 'A'&& input[pos] <= 'Z') {
    endPos = pos+1;
  }
  else {
    pos++;
  }

  for (int i= 0 ; i < n ; i++) {
    for (int p=pos; p < endPos; ) {
      if (input[p] == ')') {
	endPos = p+1;
	break;
      }
      else if (input[p] >= '0' && input[p] <= '9') {
	p = solve(p);
      }
      else if (input[p] >= 'A' && input[p] <= 'Z') {
	//	cout << input[p] << " " << p << endl;
	cnt++;
	if (cnt == target) {
	  throw input[p];
	}
	p++;
      }
    }
  }

  return endPos;
  
}

int main() {
  
  while (true) {
    cin >> input >> target;
    if (input == "0" && target == 0) {
      break;
    }
    
    //    cout << "ip: " << input << endl;
    //    cout << "t: " << target << endl;
    
    cnt = -1;
    try {
      for (int p=0 ; p < input.length()  ;) {
       p = solve(p);
       //       cout << "p: " << p << endl;
      }
      cout << 0 << endl;
    }
    catch (char c) {
      cout << c << endl;
    }
    
  }

  return 0;
}