51分求助，#1#2#3WA

#include <iostream>
#include <algorithm>
#include <string>

using namespace std;

string A[20];
int cnt[20];
int ans, n;

void DFS(const string & a, int prev)
{
    int len = a.size(), total = prev + len;
    ans = max(ans, total);
    for (int i = 1; i <= len; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (cnt[j] < 2 && A[j].size() > i && a.compare(len - i, i, A[j], 0, i) == 0)
            {
                cnt[j]++;
                DFS(A[j], total - i);
                cnt[j]--;
            }
        }
    }
}

int main()
{
    cin >> n;
    for (int i = 0; i < n; i++)
        cin >> A[i];
    char start;
    cin >> start;
    for (int i = 0; i < n; i++)
    {
        if (A[i][0] == start)
            DFS(A[i], 0);
    }
    cout << ans;
    return 0;
}