#include<bits/stdc++.h>

#ifndef ONLINE_JUDGE
#include "debug.h"
#else
#define debug(...) 42
#endif

using i64 = long long;

namespace ranges = std::ranges;

constexpr int OP = 1E9;

void solve()
{
    int n, m, k; std::cin >> n >> m >> k;
    std::string s; std::cin >> s; s = " " + s; std::vector<int> pre(n + 1); for (int i = 1; i <= n; i++) {pre[i] = pre[i - 1] + (s[i] == '0');}

    auto chmin = [&](auto& a, auto b) {a = std::min(a, b);};

    auto check = [&](int& len) {
        std::vector dp(n + 1, std::array<std::array<int, 2>, 6>()); for (auto& dpi : dp) for (auto& dpij : dpi) {ranges::fill(dpij, OP);}
        dp[0][0][0] = 0;
        for (int i = 1; i <= n; i++) for (int j = 0; j <= k; j++) {
            if (i >= len and j >= 1) {chmin(dp[i][j][1], dp[i - len][j - 1][0] + pre[i] - pre[i - len]);}
            chmin(dp[i][j][0], std::min(dp[i - 1][j][1], dp[i - 1][j][0]));
        }
        return ranges::min(dp[n][k]) <= m;
    };

    int lo{}, hi{n}; while (lo <= hi) {int mid{lo + hi >> 1}; check(mid) ? lo = mid + 1 : hi = mid - 1;}
    std::cout << lo - 1 << "\n";
}

signed main()
{
   std::cin.tie(nullptr)->sync_with_stdio(false);
   int _(1);
#ifdef tests
   std::cin >> _;
#endif
   while(_--) solve();
   return 0;
}