Problem:
Score : 700 points

Problem Statement

Nuske has a grid with N rows and M columns of squares. The rows are numbered 1 through N from top to bottom, and the columns are numbered 1 through M from left to right.
Each square in the grid is painted in either blue or white. If S_{i,j} is 1, the square at the i-th row and j-th column is blue; if S_{i,j} is 0, the square is white.
For every pair of two blue square a and b, there is at most one path that starts from a, repeatedly proceeds to an adjacent (side by side) blue square and finally reaches b, without traversing the same square more than once.

Phantom Thnook, Nuske's eternal rival, gives Q queries to Nuske. The i-th query consists of four integers x_{i,1}, y_{i,1}, x_{i,2} and y_{i,2} and asks him the following: when the rectangular region of the grid bounded by (and including) the x_{i,1}-th row, x_{i,2}-th row, y_{i,1}-th column and y_{i,2}-th column is cut out, how many connected components consisting of blue squares there are in the region?

Process all the queries.

Constraints

1 ≤ N,M ≤ 2000

1 ≤ Q ≤ 200000

S_{i,j} is either 0 or 1.

S_{i,j} satisfies the condition explained in the statement.

1 ≤ x_{i,1} ≤ x_{i,2} ≤ N(1 ≤ i ≤ Q)

1 ≤ y_{i,1} ≤ y_{i,2} ≤ M(1 ≤ i ≤ Q)

Input

The input is given from Standard Input in the following format:

N M Q
S_{1,1}..S_{1,M}
:
S_{N,1}..S_{N,M}
x_{1,1} y_{i,1} x_{i,2} y_{i,2}
:
x_{Q,1} y_{Q,1} x_{Q,2} y_{Q,2}

Output

For each query, print the number of the connected components consisting of blue squares in the region.

Sample Input 1

3 4 4
1101
0110
1101
1 1 3 4
1 1 3 1
2 2 3 4
1 2 2 4

Sample Output 1

3
2
2
2

In the first query, the whole grid is specified. There are three components consisting of blue squares, and thus 3 should be printed.

In the second query, the region within the red frame is specified. There are two components consisting of blue squares, and thus 2 should be printed.
Note that squares that belong to the same component in the original grid may belong to different components.

Sample Input 2

5 5 6
11010
01110
10101
11101
01010
1 1 5 5
1 2 4 5
2 3 3 4
3 3 3 3
3 1 3 5
1 1 3 4

Sample Output 2

3
2
1
1
3
2

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.*;
import java.math.*;
import java.util.*;
 
public class Main {
    private static boolean debug = false;
    private static boolean elapsed = true;
 
    private static PrintWriter _out = new PrintWriter(System.out);
    private static PrintWriter _err = new PrintWriter(System.err);
 
    private static class Question {
        int x1;
        int y1;
        int x2;
        int y2;
    }
    private void solve(BufferedReader in) throws IOException {
        String[] tokens;
        tokens = in.readLine().split(" ");
        int N = Integer.parseInt(tokens[0]);
        int M = Integer.parseInt(tokens[1]);
        int Q = Integer.parseInt(tokens[2]);
        boolean[][] S = new boolean[N][M];
        for (int i = 0; i < N; ++i) {
            String s = in.readLine();
            for (int j = 0; j < M; ++j) {
                S[i][j] = (s.charAt(j) == '1');
            }
        }
        List<Question> list = new ArrayList<>();
        for (int i = 0; i < Q; ++i) {
            tokens = in.readLine().split(" ");
 
            Question q = new Question();
            q.x1 = Integer.parseInt(tokens[0]);
            q.y1 = Integer.parseInt(tokens[1]);
            q.x2 = Integer.parseInt(tokens[2]);
            q.y2 = Integer.parseInt(tokens[3]);
            list.add(q);
        }
 
        boolean[][] edgeX = new boolean[N][M];
        boolean[][] edgeY = new boolean[N][M];
        for (int i = 0; i < N; ++i) {
            for (int j = 0; j < M; ++j) {
                edgeX[i][j] = (S[i][j] && i > 0 && S[i - 1][j]);
                edgeY[i][j] = (S[i][j] && j > 0 && S[i][j - 1]);
            }
        }
 
        CumulativeSum cs1 = new CumulativeSum(S, N, M);
        CumulativeSum cs2 = new CumulativeSum(edgeX, N, M);
        CumulativeSum cs3 = new CumulativeSum(edgeY, N, M);
 
        for (Question q : list) {
            _out.println(
                cs1.getSum(q.x1 - 1, q.x2, q.y1 - 1, q.y2)
                - cs2.getSum(q.x1, q.x2, q.y1 - 1, q.y2)
                - cs3.getSum(q.x1 - 1, q.x2, q.y1, q.y2));
        }
    }
    private static class CumulativeSum {
        int[][] sum;
        public CumulativeSum(boolean[][] b, int n, int m) {
            sum = new int[n + 1][m + 1];
            for (int i = 1; i <= n; ++i) {
                for (int j = 1; j <= m; ++j) {
                    sum[i][j] = sum[i - 1][j] + sum[i][j - 1] - sum[i - 1][j - 1] + (b[i - 1][j - 1] ? 1 : 0);
                }
            }
        }
        public int getSum(int t, int b, int l, int r) {
            return sum[b][r] - sum[b][l] - sum[t][r] + sum[t][l];
        }
    }
    private static BigInteger C(long n, long r) {
        BigInteger res = BigInteger.ONE;
        for (long i = n; i > n - r; --i) {
            res = res.multiply(BigInteger.valueOf(i));
        }
        for (long i = r; i > 1; --i) {
            res = res.divide(BigInteger.valueOf(i));
        }
        return res;
    }
    private static BigInteger P(long n, long r) {
        BigInteger res = BigInteger.ONE;
        for (long i = n; i > n - r; --i) {
            res = res.multiply(BigInteger.valueOf(i));
        }
        return res;
    }
    /*
     * 10^10 > Integer.MAX_VALUE = 2147483647 > 10^9
     * 10^19 > Long.MAX_VALUE = 9223372036854775807L > 10^18
     */
    public static void main(String[] args) throws IOException {
        long S = System.currentTimeMillis();
 
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        new Main().solve(in);
        _out.flush();
 
        long G = System.currentTimeMillis();
        if (elapsed) {
            _err.println((G - S) + "ms");
        }
        _err.flush();
    }
}