#include <cstring>
#include <iostream>
#include <utility>
#include <vector>
using namespace std;
using pi = pair<int, int>;
vector<int> *rows;
vector<int> *columns;
int *reverseRows;
int *reverseColumns;
int *checkedRows;
int *checkedColumns;
int checks = 0;
#define Rows \
for (int i : rows[pos.second]) { \
int found = depths[pos.second][i]; \
if (found <= depth + 1) continue; \
\
int ret = find<false>(depths, depth + 1, { i, pos.second }, min); \
if (ret) return ret - 1; \
}
#define Columns \
for (int i : columns[pos.first]) { \
int found = depths[i][pos.first]; \
if (found <= depth + 1) continue; \
\
int ret = find<true>(depths, depth + 1, { pos.first, i }, min); \
if (ret) return ret - 1; \
}
#define Check \
if (depth + 1 >= *min) return depth + 2 - *min;
template<bool Row>
int find(int **depths, int depth, pi pos, int *min) {
checks++;
depths[pos.second][pos.first] = depth;
Check
if (depth > checkedRows[pos.second]) return depth - checkedRows[pos.second];
if (depth > checkedColumns[pos.first]) return depth - checkedColumns[pos.first];
checkedRows[pos.second] = depth + 1;
checkedColumns[pos.first] = depth + 1;
int revRow = reverseRows[pos.second];
int revCol = reverseColumns[pos.first];
if (revRow) {
if (revCol && revCol < revRow) {
*min = depth + revCol - 1;
return revCol - 1;
} else {
*min = depth + revRow - 1;
return revRow - 1;
}
} else if (revCol) {
*min = depth + revCol - 1;
return revCol - 1;
}
if constexpr (Row) {
Rows
Columns
} else {
Columns
Check
Rows
}
return false;
}
void createReverse(pi pos, int depth, int max) {
if (reverseRows[pos.second] == 0 || depth < reverseRows[pos.second]) reverseRows[pos.second] = depth;
if (reverseColumns[pos.first] == 0 || depth < reverseColumns[pos.first]) reverseColumns[pos.first] = depth;
if (depth >= max) return;
for (int i : rows[pos.second]) {
createReverse({ i, pos.second }, depth + 1, max);
}
for (int i : columns[pos.first]) {
createReverse({ pos.first, i }, depth + 1, max);
}
}
int getDepth(pi start, pi end, int height, int width, int **depths) {
if (start.first == end.first && start.second == end.second) return 0;
for (int i = 0; i < height; i++)
memset((void*)(depths[i]), 127, width * sizeof(int));
memset((void*)reverseRows, 0, height * sizeof(int));
memset((void*)reverseColumns, 0, width * sizeof(int));
memset((void*)checkedRows, 127, height * sizeof(int));
memset((void*)checkedColumns, 127, width * sizeof(int));
createReverse(end, 1, 2);
int min = 42069;
find<true>(depths, 1, start, &min);
if (min == 42069) return -1;
return min;
}
int main(int argc, char *argv[]) {
int height, width, count; cin >> height >> width >> count;
rows = new vector<int>[height];
columns = new vector<int>[width];
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
char c; cin >> c;
if (c == '.') {
rows[y].push_back(x);
columns[x].push_back(y);
}
}
}
reverseRows = new int[height];
reverseColumns = new int[width];
checkedRows = new int[height];
checkedColumns = new int[width];
int **depths = new int*[height];
for (int i = 0; i < height; i++) depths[i] = new int[width];
for (int i = 0; i < count; i++) {
int y1, x1, y2, x2; cin >> y1 >> x1 >> y2 >> x2;
pi start{ x1 - 1, y1 - 1 };
pi end{ x2 - 1, y2 - 1 };
int min = getDepth(start, end, height, width, depths);
cout << min << endl;
}