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
#define make_pair mp
#define emplace_back pb
#include <bits/stdc++.h>
using namespace std;
mt19937 mt_rand(time(0));
const int N = 8e3 + 5, INF = 1e5;
int n, k, t, ile;
int dp[N][N][3], tab[N];
char s[N];
int main()
{
	scanf("%d %d %d", &n, &k, &t);
	k = min(n, k);
	scanf("%s", s);
	for(int i=0;i<=n;i++) {
		dp[0][i][0] = 0;
		dp[0][i][1] = -INF; 
		dp[0][i][2] = -INF; 
	}
	for(int i=1;i<=n;i++) for(int j=0;j<=n;j++) {
		dp[i][j][0] = -INF;
		dp[i][j][1] = -INF;
		dp[i][j][2] = -INF;
	}
	for(int i=1;i<=n;i++) {
		if(s[i-1] != '3') ile++;
		for(int j=0;j<=n;j++) {
			if(s[i-1] == '3') {
				dp[i][j][0] = dp[i-1][j][0] + 1;
				dp[i][j][1] = dp[i-1][j][1];
				dp[i][j][2] = dp[i-1][j][2] + 1;
			}
			else if(s[i-1] == '2') {
				dp[i][j][0] = dp[i-1][j][0];
				dp[i][j][1] = dp[i-1][j][1];
				dp[i][j][2] = dp[i-1][j][2];
				if(j >= 1) {
					dp[i][j][0] = max(dp[i][j][0], dp[i-1][j-1][0] + 1);
					dp[i][j][1] = max(dp[i][j][1], dp[i-1][j-1][1] + 1);
					dp[i][j][2] = max(dp[i][j][2], dp[i-1][j-1][2] + 1);
				}
			}  else {
				dp[i][j][1] = dp[i-1][j][1];
				if(j >= 1) {
					dp[i][j][0] = max(dp[i][j][0], dp[i-1][j-1][0] + 1);
					dp[i][j][2] = max(dp[i][j][2], dp[i-1][j-1][2] + 1);
				}
			}
			if(j >= ile && i >=t) {
				dp[i][j][1] = max(dp[i][j][1], dp[i-t][j-ile][0]);
				dp[i][j][2] = max(dp[i][j][2], dp[i-t][j-ile][1]);
			}
		}
		if(i >= t) {
			if(s[i-t] != '3') ile--;
		}
	}
	dp[n][k][0] = max(dp[n][k][0], dp[n][k][2]);
	if(dp[n][k][0] < 0) printf("-1");
	else printf("%d", dp[n][k][0]);
	return 0;
}