#include<unordered_map>
#include<functional>
#include<algorithm>
#include<iostream>
#include<cassert>
#include<cstring>
#include<cstdlib>
#include<numeric>
#include<iomanip>
#include<bitset>
#include<random>
#include<cstdio>
#include<string>
#include<vector>
#include<array>
#include<ctime>
#include<stack>
#include<queue>
#include<cmath>
#include<set>
#include<map>

#define fi first
#define se second
#define pii pair<int,int>
#define NO cout << "NO\n"
#define YES cout << "YES\n"
#define stop system("pause");
#define debug printf("++ ++\n");
#define cout(a) cout << (#a) << " = " << a << endl;
using namespace std;
typedef long long ll;
const int INF = 0x3f3f3f3f;
const int N = 2e5;
const int K = 5;
random_device gen;
mt19937 rnd(gen());
int n, m, k;
int sum[N + 5], dp[N + 5][K + 5];
//dp[i][j]表示处理到第 i 位时, 前面已经存在 j 个 >m 的 '1' 串
char s[N + 5];

/* 终点是一切概率的结束，也是一切期望的开始 */
/* *
 * 可能做法: 基础算法(思维, 暴力, 贪心, 二分dp)
 * */

bool check(int mid) {
	for (int i = 0; i <= n; i++) for (int j = 0; j <= k; j++) dp[i][j] = INF;
	dp[0][0] = 0;
	for (int i = mid; i <= n; i++) {
		int l = i - mid + 1, r = i;
		for (int j = k; j >= 0; j--) {
			dp[i][j] = dp[i - 1][j];
			if (s[l - 1] == '0' && j >= 1) dp[i][j] = min(dp[i][j], dp[max(0, l - 2)][j - 1] + (sum[r] - sum[l - 1]));
		}
	}
//	cout (dp[n][k]);
	return dp[n][k] <= m;
}

void solve() {
	cin >> n >> m >> k >> (s + 1);
	s[0] = '0';
	for (int i = 1; i <= n; i++) sum[i] = sum[i - 1] + (s[i] == '0');
	int l = 1, r = n, ans = -1;
//	cout << boolalpha << check(3) << endl;
	while (l <= r) {
		int mid = l + r >> 1;
		if (check(mid)) ans = mid, l = mid + 1;
		else r = mid - 1;
	}
	cout << ans << '\n';
}

signed main() {
	std::ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
	int t = 1;
//	cin >> t;
	while (t--) solve();
	return 0;
}

answer.code: In function ‘void solve()’:
answer.code:63:28: error: no match for ‘operator>>’ (operand types are ‘std::basic_istream<char>::__istream_type’ {aka ‘std::basic_istream<char>’} and ‘char*’)
   63 |         cin >> n >> m >> k >> (s + 1);
      |         ~~~~~~~~~~~~~~~~~~ ^~ ~~~~~~~
      |                       |          |
      |                       |          char*
      |                       std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}
In file included from /usr/include/c++/11/iostream:40,
                 from answer.code:4:
/usr/include/c++/11/istream:168:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match)
  168 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/11/istream:168:7: note:   conversion of argument 1 would be ill-formed:
answer.code:63:34: error: cannot bind non-const lvalue reference of type ‘bool&’ to a value of type ‘char*’
   63 |         cin >> n >> m >> k >> (s + 1);
      |                               ~~~^~~~
In file included from /usr/include/c++/11/iostream:40,
                 from answer.code:4:
/usr/include/c++/11/istream:172:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]’ (near match)
  172 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/11/istream:172:7: note:   conversion of argument 1 would be ill-formed:
answer.code:63:34: error: invalid conversion from ‘char*’ to ‘short int’ [-fpermissive]
   63 |         cin >> n >> m >> k >> (s + 1);
      |                               ~~~^~~~
      |                                  |
      |                                  char*
answer.code:63:34: error: cannot bind rvalue ‘(short int)(((char*)(& s)) + 1)’ to ‘short int&’
In file included from /usr/include/c++/11/iostream:40,
                 from answer.code:4:
/usr/include/c++/11/istream:175:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match)
  175 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/11/istream:175:7: note:   conversion of argument 1 would be ill-formed:
answer.code:63:34: error: invalid conversion from ‘char*’ to ‘short unsigned int’ [-fpermissive]
   63 |         cin >> n >> m >> k >> (s + 1);
      |                               ~~~^~~~
      |                                  |
      |                                  char*
answer.code:63:34: error: cannot bind rvalue ‘(short unsigned int)(((char*)(& s)) + 1)’ to ‘short unsigned int&’
In file included from /usr/include/c++/11/iostream:40,
                 from answer.code:4:
/usr/include/c++/11/istream:179:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]’ (near match)
  179 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/11/istream:179:7: note:   conversion of argument 1 would be ill-formed:
answer.code:63:34: error: invalid conversion from ‘char*’ to ‘int’ [-fpermissive]
   63 |         cin >> n >> m >> k >> (s + 1);
      |                               ~~~^~~~
      |                                  |
      |                                  char*
answer.code:63:34: error: cannot bind rvalue ‘(int)(((char*)(& s)) + 1)’ to ‘int&’
In file included from /usr/include/c++/11/iostream:40,
                 from answer.code:4:
/usr/include/c++/11/istream:182:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::__istream_type = std::basic_istream<char>]’ (near match)
  182 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/11/istream:182:7: note:   conversion of argument 1 would be ill-formed:
answer.code:63:34: error: invalid conversion from ‘char*’ to ‘unsigned int’ [-fpermissive]
   63 |         cin >> n >> m >> k >> (s + 1);
      |                               ~~~^~~~
      |                                  |
      |                                  char*
answer.code:63:34: error: cannot bind rvalue ‘(unsigned int)(((char*)(& s)) + 1)’ to ‘unsigned int&’
In file included from /usr/include/c++/11/iostream:40,
                 from answer.code:4:
/usr/include/c++/11/istream:186:7: note: candidate: ‘std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _T...