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const int maxn = 18;
const int mod = 1000000007;
int dp[maxn][maxn][maxn][maxn][maxn][7];
int list[200];
int equal(int a, int b) {
if (a == b)
return 1;
return 0;
}
int dfs(int a, int b, int c, int d, int e, int last){
if(dp[a][b][c][d][e][last] != -1)
return dp[a][b][c][d][e][last];
if(a + b + c + d + e == 0)
return 1;
int ans = 0;
if (a) ans = (ans + (a - equal(last, 2)) * dfs(a - 1, b, c, d, e, 1)) % mod;
if (b) ans = (ans + (b - equal(last, 3)) * dfs(a + 1, b - 1, c, d, e, 2)) % mod;
if (c) ans = (ans + (c - equal(last, 4)) * dfs(a, b + 1, c - 1, d, e, 3)) % mod;
if (d) ans = (ans + (d - equal(last, 5)) * dfs(a, b, c + 1, d - 1, e, 4)) % mod;
if (e) ans = (ans + e * dfs(a, b, c, d + 1, e - 1, 5)) % mod;
dp[a][b][c][d][e][last] = ans % mod;
return dp[a][b][c][d][e][last];
}
int cns[20];
int main(){
int n = getint();
int i = 0;
while (i < maxn) {
int j = 0;
while(j < maxn) {
int k = 0;
while(k < maxn) {
int l = 0;
while (l < maxn) {
int m = 0;
while (m < maxn) {
int h = 0;
while (h < 7) {
dp[i][j][k][l][m][h] = -1;
h = h + 1;
}
m = m + 1;
}
l = l + 1;
}
k = k + 1;
}
j = j + 1;
}
i = i + 1;
}
i = 0;
while (i < n) {
list[i] = getint();
cns[list[i]] = cns[list[i]] + 1;
i = i + 1;
}
int ans = dfs(cns[1], cns[2], cns[3], cns[4], cns[5], 0);
putint(ans);
return ans;
}
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