#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i= (a); i<((int)b); ++i)
#define RFOR(i,a) for(int i=(a); i >= 0; --i)
#define FOE(i,a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v,x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT_ON(bit, i) (bit & (1LL << i))
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());

typedef long long LL;
template<typename T> using V = std::vector<T>;
template<typename T> using VV = std::vector<std::vector<T>>;
template<typename T> using VVV = std::vector<std::vector<std::vector<T>>>;
template<typename T> using VVVV = std::vector<std::vector<std::vector<std::vector<T>>>>;

template<class T> inline T ceil(T a, T b) { return (a + b - 1) / b; }
template<class T> inline void print(T x) { std::cout << x << std::endl; }
template<class T> inline void print_vec(const std::vector<T> &v) { for (int i = 0; i < v.size(); ++i) {  if (i != 0) {std::cout << " ";} std::cout << v[i];} std::cout << "\n"; }
template<class T> inline bool inside(T y, T x, T H, T W) {return 0 <= y and y < H and 0 <= x and x < W; }
template<class T> inline double euclidean_distance(T y1, T x1, T y2, T x2) { return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); }
template<class T> inline double manhattan_distance(T y1, T x1, T y2, T x2) { return abs(x1 - x2) + abs(y1 - y2); }

const int INF = 1L << 30;
const double EPS = 1e-9;
const std::string YES = "YES", Yes = "Yes", NO = "NO", No = "No";
const std::vector<int> dy4 = { 0, 1, 0, -1 }, dx4 = { 1, 0, -1, 0 };    // 4近傍（右, 下, 左, 上）
const std::vector<int> dy8 = { 0, -1, 0, 1, 1, -1, -1, 1 }, dx8 = { 1, 0, -1, 0, 1, 1, -1, -1 };

using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    while (true) {
        int X, Y, Z;
        cin >> X >> Y >> Z;
        if (X + Y + Z == 0) {
            break;
        }

        V<int> v(X), E(Y + 1), A(Y + 1);
        FOR(i, 0, X) {
            cin >> v[i];
        }
        FOR(i, 0, Z) {
            int n;
            cin >> n;
            cin >> E[n] >> A[n];
        }

        VV<double> dp(Y + 1, V<double>(5001, 0));
        dp[0][0] = 1.0;

        double ans = 0.0;
        FOR(p, 0, Y + 1) {
            FOR(m, 0, 5001) {
                if (dp[p][m] == 0) {
                    continue;
                }

                FOR(k, 0, X) {
                    int next_p = p + v[k];

                    // ゴール
                    if (next_p >= Y or (E[next_p] == 1 and next_p + A[next_p] >= Y)) {
                        ans += m * dp[p][m] * (1.0 / X);
                    }
                    // forward
                    else if (E[next_p] == 1) {
                        dp[next_p + A[next_p]][m] += dp[p][m] * (1.0 / X);
                    }
                    // get money
                    else if (E[next_p] == 2) {
                        dp[next_p][m + A[next_p]] += dp[p][m] * (1.0 / X);
                    }
                    // lost money
                    else if (E[next_p] == 3) {
                        dp[next_p][max(0, m - A[next_p])] += dp[p][m] * (1.0 / X);
                    }
                    else {
                        dp[next_p][m] += dp[p][m] * (1.0 / X);
                    }
                }
            }
        }
        print(int(ans));

    }
    return 0;
}


Measured memory_bytes: 4984