求助WA，dalao帮忙看看这个暴力哪里错了

#include<iostream>
#include<cstdio>
using namespace std;
const int mod = 1e9 + 7;
const int maxL_a = 1005;
const int maxL_b = 205;
const int maxk = 205;

char a[maxL_a], b[maxL_b];
int n, m, k, dp[maxL_a][maxL_b][maxk][2];
int main() {
    scanf("%d%d%d", &n, &m, &k);
    scanf("%s%s", a + 1, b + 1);
    dp[0][0][0][0] = dp[0][0][0][1] = 1;
    for(int i = 1;i <= n;i++) {
        for(int j = 1;j <= m;j++) {
            for(int p = 1;p <= k;p++) {
                dp[i][j][p][0] = dp[i - 1][j][p][0] + dp[i - 1][j][p][1];
                if(a[i] == b[j]) {
                    dp[i][j][p][1] += dp[i - 1][j - 1][p][1];
                    dp[i][j][p][1] += dp[i - 1][j - 1][p - 1][0];
                    dp[i][j][p][1] += dp[i - 1][j - 1][p - 1][1];
                } else {
                    dp[i][j][p][1] = 0;
                }
            }
        }
    }
    printf("%d\n", dp[n][m][k][0] + dp[n][m][k][1]);
    return 0;
}