#include <bits/stdc++.h>   using namespace std;   long long d[111111];   long long sum[111111];   int q[111111];   long long cat[111111];   long long dp[101][100001];   long long getDP(int i, int j, int k) {     return (long long)j * cat[j] + dp[i - 1][k] - j * cat[k];   }   long long getUP(int i, int j, int k) {     return (long long)dp[i - 1][j] - dp[i - 1][k];   }   long long getDOWN(int j, int k) { return (long long)cat[j] - cat[k]; }   int main() {     int i, j, k, n, m, p, h;     cin >> n >> m >> p;     for (i = 2; i <= n; i++) {       cin >> d[i];       d[i] += d[i - 1];     }     for (i = 1; i <= m; i++) {       cin >> h >> cat[i];       cat[i] -= d[h];     }     sort(cat + 1, cat + 1 + m);     for (i = 1; i <= m; i++) sum[i] = sum[i - 1] + cat[i];     for (i = 1; i <= p; i++)       for (j = 1; j <= m; j++) dp[i][j] = 999999999999999;     dp[1][m] = (long long)m * cat[m] - sum[m];     for (i = 2; i <= p; i++) {       int head, tail;       head = tail = 0;       q[tail++] = m;       for (j = m; j >= 1; j--) {         while (head + 1 < tail && (getUP(i, q[head + 1], q[head]) <=                                    j * getDOWN(q[head + 1], q[head])))           head++;         dp[i][j] = min(dp[i][j], getDP(i, j, q[head]));         while (head + 1 < tail &&                getUP(i, j, q[tail - 1]) * getDOWN(q[tail - 1], q[tail - 2]) >                    getUP(i, q[tail - 1], q[tail - 2]) * getDOWN(j, q[tail - 1]))           tail--;         q[tail++] = j;       }     }     long long ans = dp[p][1];     for (i = 1; i <= m; i++) ans = min(ans, dp[p][i]);     cout << ans << endl;   }   