//rename file to Main.java
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
        long ans = 0;
        long flippedAns = 0;
        long[][] A = readMatrix(input);
        int l = Integer.parseInt(input.readLine());
        for (int k = 0; k < l; k++) {
            String str = input.readLine();
            StringTokenizer data = new StringTokenizer(str);
            int i = Integer.parseInt(data.nextToken())-1;
            int j = Integer.parseInt(data.nextToken())-1;
            if (ans != -1) {
                try {
                    ans += A[i][j];
                } catch (ArrayIndexOutOfBoundsException e) {
                    ans = -1;
                }
            }

            if (flippedAns != -1) {
                try {
                    flippedAns += A[j][i];
                } catch (ArrayIndexOutOfBoundsException e) {
                    flippedAns = -1;
                }
            }
        }
        System.out.println(Math.max(ans, flippedAns));
    }

    private static long[][] readMatrix(BufferedReader input) throws IOException {
        String str = input.readLine();
        StringTokenizer data = new StringTokenizer(str);
        int n = Integer.parseInt(data.nextToken());
        int m = Integer.parseInt(data.nextToken());
        long[][] A = new long[n][m];
        for (int i = 0; i < n; i++) {
            str = input.readLine();
            data = new StringTokenizer(str);
            for (int j = 0; j < m; j++) {
                A[i][j] = Long.parseLong(data.nextToken());
            }
        }
        return A;
    }


}