#include <bits/stdc++.h>

using namespace std;

#define REP(i,first,last) for (int i=first;i<last;++i)
#define MAX(x,y) (x > y ? x : y)
#define MIN(x,y) (x < y ? x : y)

int N, K;

int main(){
  cin >> N >> K;
  vector<char> ice_box(N);
  REP(i,0,N){
    cin >> ice_box[i];
  }

  queue<int> que;
  int buy = 0;
  int eat = 0;
  int idx = 0;

  while (eat < K) {
    if (que.empty()) {
      switch (ice_box[idx]) {
        case '0':
          idx += 1;
          break;
        case '1':
          que.push(ice_box[(idx + 1) % N]);
          idx += 2;
          break;
        case '2':
          que.push(ice_box[(idx + 1) % N]);
          que.push(ice_box[(idx + 2) % N]);
          idx += 3;
      }
      ++buy;
    } else {
      char ice = que.front();
      que.pop();

      switch (ice) {
        case '0':
          break;
        case '1':
          que.push(ice_box[idx]);
          idx += 1;
          break;
        case '2':
          que.push(ice_box[idx]);
          que.push(ice_box[(idx + 1) % N]);
          idx += 2;
      }
    }

    idx %= N;
    ++eat;
  }

  cout << buy << endl;
}