#include<bits/stdc++.h>
#include<unordered_map>
#include<unordered_set>
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
#define debug(a) cout<<a<<'\n'
#define Pll pair<ll,ll>
#define PII pair<int,int>
#define ft first
#define sd second
#define vec vector
#define pushk push_back
#define ump unordered_map
#define pl p<<1
#define pr p<<1|1
using namespace std;
const int N = 2e5 + 10, M = 1e4 + 10, mod = 1e9+7;
const ll inf = 1e18;
const ld eps = 1e-13;
int mov[4][2] = { {0,1},{1,0},{-1,0},{0,-1} }, dx, dy, _ = 1, __ = 1;
void bout(bool f) {
	if (f)cout << "YES\n";
	else cout << "NO\n";
}
ll n, m, k;
string s;
int dp[N][6],sum[N],l[N];

bool check(int len){
	if(len<=0)return 0;
	memset(dp,0x3f,sizeof dp);
	dp[0][0]=0;
	for(int i=1;i<=n;++i){
		for(int j=0;j<=k;++j){
			dp[i][j]=min(dp[i][j],dp[i-1][j]);
			if(j&&i>=len){
				if(s[i-len]=='1'){
					if(l[i-len]>1)dp[i][j]=min(dp[i][j],dp[l[i-len]-2][j-1]+len-sum[i]+sum[i-len]);
					else dp[i][j]=min(dp[i][j],dp[0][j-1]+len-s[i]+s[i-len]);//l[i]==1
				}else{
					if(i-len>0)dp[i][j]=min(dp[i][j],dp[i-len-1][j-1]+len-sum[i]+sum[i-len]);
					else dp[i][j]=min(dp[i][j],dp[0][j-1]+len-sum[i]);//i-len==0 i=len
				}
			}
		}
	}
	return dp[n][k]<=m;
}

void ini() {

}
void solve() {
	cin>>n>>m>>k;
	cin>>s;
	s='#'+s;
	for(int i=1;i<=n;++i){
		if(s[i]=='1'){
			if(s[i-1]=='1')l[i]=l[i-1];
			else l[i]=i;
		}
		sum[i]=sum[i-1]+(s[i]=='1');
	}
	int lp=-1,rp=n+1,mid;
	while(lp<rp-1){
		mid=lp+rp>>1;
		if(check(mid))lp=mid;
		else rp=mid;
	}
	cout<<lp;
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
#ifndef ONLINE_JUDGE
	streambuf *cinbp=cin.rdbuf(),*coutbp=cout.rdbuf();
	ifstream fin("in.txt");
	ofstream fout("out.txt");	
	cin.rdbuf(fin.rdbuf());
	cout.rdbuf(fout.rdbuf());
#endif
	//cin >> _;
	__ = _;
	ini();
	while (_--) {
		solve();
	}
	return 0;
}