Zxr960115 is owner of a large farm. He feeds m cute cats and employs p feeders. There's a straight road across the farm and n hills along the road, numbered from 1 to n from left to right. The distance between hill i and (i - 1) is di meters. The feeders live in hill 1.

One day, the cats went out to play. Cat i went on a trip to hill hi, finished its trip at time ti, and then waited at hill hi for a feeder. The feeders must take all the cats. Each feeder goes straightly from hill 1 to n without waiting at a hill and takes all the waiting cats at each hill away. Feeders walk at a speed of 1 meter per unit time and are strong enough to take as many cats as they want.

For example, suppose we have two hills (d2 = 1) and one cat that finished its trip at time 3 at hill 2 (h1 = 2). Then if the feeder leaves hill 1 at time 2 or at time 3, he can take this cat, but if he leaves hill 1 at time 1 he can't take it. If the feeder leaves hill 1 at time 2, the cat waits him for 0 time units, if the feeder leaves hill 1 at time 3, the cat waits him for 1 time units.

Your task is to schedule the time leaving from hill 1 for each feeder so that the sum of the waiting time of all cats is minimized.

Input

The first line of the input contains three integers n, m, p (2 ≤ n ≤ 105, 1 ≤ m ≤ 105, 1 ≤ p ≤ 100).

The second line contains n - 1 positive integers d2, d3, ..., dn (1 ≤ di < 104).

Each of the next m lines contains two integers hi and ti (1 ≤ hi ≤ n, 0 ≤ ti ≤ 109).

Output

Output an integer, the minimum sum of waiting time of all cats.

Please, do not write the %lld specifier to read or write 64-bit integers in С++. It is preferred to use the cin, cout streams or the %I64d specifier.

Examples

Input

4 6 2
1 3 5
1 0
2 1
4 9
1 10
2 10
3 12


Output

3

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.StringTokenizer;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
/**
 *
 * @author Trung Pham
 */
public class D {

    private static int MOD = 1000000007;
    static long[] a, s;
    static Point[] q;

    public static void main(String[] args) {
        Scanner in = new Scanner();
        PrintWriter out = new PrintWriter(System.out);
        int n = in.nextInt();
        int m = in.nextInt();
        int p = in.nextInt();
        q = new Point[m + 1];
        int[] d = new int[n + 1];
        for (int i = 2; i <= n; i++) {
            d[i] = in.nextInt();
        }
        int[] h = new int[m + 1];
        int[] t = new int[m + 1];
        for (int i = 1; i <= m; i++) {
            h[i] = in.nextInt();
            t[i] = in.nextInt();
        }
        int[] sum = new int[n+ 1];
        for (int i = 2; i <= n; i++) {
            sum[i] = sum[i - 1] + d[i];
        }
        a = new long[m + 1];
        for (int i = 1; i <= m; i++) {
            a[i] = t[i] - sum[h[i]];
        }
        Arrays.sort(a,1,m+ 1);
        s = new long[m + 1];        
        for (int i = 1; i <= m; i++) {
            s[i] = s[i - 1] + a[i];
        }
        long[][] dp = new long[p + 1][m + 1];
        
        dp[0][0] = 0;
       // System.out.println(sum.length);
        for (int i = 1; i <= m; i++) {
            dp[1][i] = a[i] * i - s[i];
        }
        for (int i = 2; i <= p; i++) {
            int l = 0, r = 0;
            for (int j = 1; j <= m; j++) {
                Point point = new Point(j, dp[i - 1][j] + s[j]);
                while (r - l >= 2 && cross(minus(q[r - 1], q[r - 2]), minus(point, q[r - 1])) <= 0) {
                    r--;
                }
                q[r++] = point;
                while (r - l >= 2 && q[l + 1].y - q[l].y <= a[j] * (q[l + 1].x - q[l].x)) {
                    l++;
                }
                dp[i][j] = dp[i - 1][(int)q[l].x] + a[j]*(j - q[l].x) - s[j] + s[(int)q[l].x];
                //System.out.println(dp[i][j]);
            }
        }
        out.println(dp[p][m]);
        out.close();


    }

    static Point minus(Point a, Point b) {
        return new Point(a.x - b.x, a.y - b.y);
    }

    static long cross(Point a, Point b) {
        return a.x * b.y - a.y * b.x;
    }

    static class Point {

        long x, y;

        public Point(long x, long y) {
            this.x = x;
            this.y = y;
        }
    }

    public boolean nextPer(int[] data) {
        int i = data.length - 1;
        while (i > 0 && data[i] < data[i - 1]) {
            i--;
        }
        if (i == 0) {
            return false;
        }
        int j = data.length - 1;
        while (data[j] < data[i - 1]) {
            j--;
        }
        int temp = data[i - 1];
        data[i - 1] = data[j];
        data[j] = temp;
        Arrays.sort(data, i, data.length);
        return true;
    }

    static long pow(int a, int b) {
        if (b == 0) {
            return 1;
        }
        if (b == 1) {
            return a;
        }
        long val = pow(a, b / 2);
        if (b % 2 == 0) {
            return val * val % MOD;
        } else {
            return a * val * val % MOD;
        }
    }

    static class Scanner {

        BufferedReader br;
        StringTokenizer st;

        public Scanner() {
            //System.setOut(new PrintStream(new BufferedOutputStream(System.out), true));
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        public String next() {


            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (Exception e) {
                    throw new RuntimeException();
                }
            }
            return st.nextToken();
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public double nextDouble() {
            return Double.parseDouble(next());
        }

        public String nextLine() {
            st = null;
            try {
                return br.readLine();
            } catch (Exception e) {
                throw new RuntimeException();
            }
        }

        public boolean endLine() {
            try {
                String next = br.readLine();
                while (next != null && next.trim().isEmpty()) {
                    next = br.readLine();
                }
                if (next == null) {
                    return true;
                }
                st = new StringTokenizer(next);
                return st.hasMoreTokens();
            } catch (Exception e) {
                throw new RuntimeException();
            }
        }
    }
}
