1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ii pair<int,int>
#define iii tuple<int,int,int>
#define fi first
#define se second
#define endl '\n'

#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound

#define rep(x,start,end) for(int x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

int n,k,t;
string s;

int p1[8005];
int p2[8005];
int p3[8005];

int solve(int cnt1,int cnt2,int cnt3,int k){
	if (cnt1>k || k<0) return -1;
	return cnt3+min(cnt2,k-cnt1)+cnt1;
}

signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	cin>>n>>k>>t;
	cin>>s; s="$"+s;
	
	rep(x,1,n+1) p1[x]=p1[x-1]+(s[x]=='1');
	rep(x,1,n+1) p2[x]=p2[x-1]+(s[x]=='2');
	rep(x,1,n+1) p3[x]=p3[x-1]+(s[x]=='3');
	
	int ans=solve(p1[n],p2[n],p3[n],k);
	
	rep(x,t,n-t+1) rep(y,x+1,n-t+2){
		int cnt3=p3[x-t]+p3[n]-p3[(y+t)-1];
		int cnt2=p2[x-t]+p2[n]-p2[(y+t)-1];
		int cnt1=p1[x-t]+p1[n]-p1[(y+t)-1];
		int cnt0=(p1[x]-p1[x-t])+(p1[(y+t)-1]-p1[y-1])+(p2[x]-p2[x-t])+(p2[(y+t)-1]-p2[y-1]);
		
		// cout<<x<<" "<<y<<" "<<cnt1<<" "<<cnt2<<" "<<cnt3<<" "<<k-cnt0<<endl;
		// cout<<solve(cnt1,cnt2,cnt3,k-cnt0)<<endl;
		ans=max(ans,solve(cnt1,cnt2,cnt3,k-cnt0));
	}
	
	cout<<ans<<endl;
}