#include <bits/stdc++.h>   using namespace std;   inline void Input_Output() {}   const double eps = 0.000001;   const long double pi = acos(-1);   const int maxn = 1e7 + 9;   const int mod = 1e9 + 7;   const long long MOD = 1e18 + 9;   const long long INF = 1e18 + 123;   const int inf = 2e9 + 11;   const int mxn = 1e6 + 9;   const int N = 6e5 + 123;   const int K = 80;   const int pri = 997;   const int Magic = 2101;   const int dx[] = {-1, 0, 1, 0};   const int dy[] = {0, -1, 0, 1};   int n, m, k, x;   vector<int> state;   int ids[(1 << 8)];   struct Mat {     long long d[K][K];     Mat(long long val = INF) {       for (int i = 0; i < K; ++i)         for (int j = 0; j < K; ++j) d[i][j] = INF;       for (int i = 0; i < K; ++i) d[i][i] = val;     }     Mat operator+(Mat &b) {       Mat res;       for (int i = 0; i < K; ++i)         for (int j = 0; j < K; ++j)           for (int k = 0; k < K; ++k)             res.d[i][j] = min(res.d[i][j], d[i][k] + b.d[k][j]);       return res;     }     void print() {       for (int i = 0; i < K; ++i) {         for (int j = 0; j < K; ++j) {           if (d[i][j] == INF) {             cout <<  bd  ;             continue;           }           cout << d[i][j] <<    ;         }         cout <<   n ;       }     }   };   Mat make_matrix(vector<long long> &c) {     assert((int)(c.size()) == k);     Mat res;     for (int id = 0; id < (int)(state.size()); ++id) {       int msk = state[id];       if (msk % 2 == 0) {         int nmsk = msk / 2;         res.d[id][ids[nmsk]] = 0;         continue;       }       for (int i = 0; i < k; ++i) {         int nmsk = (msk >> 1);         if (nmsk & (1 << i)) {           continue;         }         nmsk |= (1 << i);         res.d[id][ids[nmsk]] = min(res.d[id][ids[nmsk]], c[i]);       }     }     return res;   }   int main() {     ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);     cin >> x >> k >> n >> m;     for (int msk = 0; msk < (1 << k); ++msk) {       ids[msk] = -1;       if (__builtin_popcount(msk) != x) {         continue;       }       ids[msk] = (int)(state.size());       state.push_back(msk);     }     vector<long long> c(k);     for (auto &e : c) cin >> e;     vector<int> pos = {0, n - x};     vector<pair<int, int> > spec(m);     for (auto &it : spec) {       cin >> it.first >> it.second;       it.first--;       for (int i = 0; i <= k; ++i) {         int s = it.first - i;         s = max(s, 0);         s = min(s, n - x);         pos.push_back(s);       }     }     sort(pos.begin(), pos.end());     pos.resize(unique(pos.begin(), pos.end()) - pos.begin());     vector<Mat> Pw;     Pw.push_back(make_matrix(c));     int bit = 0;     while ((1 << bit) <= n) {       ++bit;       Pw.push_back(Pw.back() + Pw.back());     }     Mat cur = 0;     for (int it = 0; it + 1 < (int)(pos.size()); ++it) {       int l = pos[it], r = pos[it + 1];       vector<long long> nc = c;       for (auto s : spec) {         if (s.first > l && s.first <= l + k) {           nc[s.first - l - 1] += s.second;         }       }       if (nc != c) {         Mat cn = make_matrix(nc);         cur = cur + cn;       } else {         int dif = r - l;         for (int i = 0; i < (int)(Pw.size()); ++i) {           if (dif & (1 << i)) {             cur = cur + Pw[i];           }         }       }     }     int fin = (1 << x) - 1;     fin = ids[fin];     assert(fin != -1);     cout << cur.d[fin][fin] <<   n ;     return 0;   }