use std::io;
use std::collections::{HashMap, HashSet, VecDeque};
use rand::{random, random_bool, random_range};
//use std::time::{SystemTime, UNIX_EPOCH};
fn main() {
let mut input = String::new();
io::stdin().read_line(&mut input).expect("Failed to read input");
let startdata: Vec<usize> = input.split_whitespace().map(|e| e.parse::<usize>().unwrap()).collect();
let mut rowgrid: Vec<Vec<usize>> = vec!();
let mut colgrid: Vec<Vec<usize>> = vec!();
let mut nodes: Vec<(usize, usize)> = vec!();
for row in 0..startdata[0] {
rowgrid.push(Vec::new());
let mut rowinput = String::new();
io::stdin().read_line(&mut rowinput).expect("Failed to read input");
let bytes = rowinput.into_bytes();
for c in 0..startdata[1] {
if row == 0 {
colgrid.push(Vec::new());
}
if bytes[c] == 46 {
rowgrid[row].push(c);
colgrid[c].push(row);
}
/*if random_bool(0.2) {
rowgrid[row].push(c);
colgrid[c].push(row);
nodes.push((row, c));
}*/
}
}
dbg!(&rowgrid);
let mut rowtorow: HashMap<usize, HashSet<usize>> = HashMap::new();
for row in 0..rowgrid.len() {
rowtorow.insert(row, HashSet::new());
for node in rowgrid[row].iter() {
for rowneighbor in colgrid[*node].iter() {
if *rowneighbor != row {
rowtorow.entry(row).and_modify(|v| {v.insert(*rowneighbor);});
}
}
}
}
'question: for _q in 0..startdata[2] {
let mut questioninput = String::new();
io::stdin().read_line(&mut questioninput).expect("Failed to read input");
let questiondata: Vec<usize> = questioninput.split_whitespace().map(|e| e.parse::<usize>().unwrap()-1).collect();
let source = (questiondata[0], questiondata[1]);
let dest = (questiondata[2], questiondata[3]);
//let source = nodes[random_range(0..nodes.len())];
//let dest = nodes[random_range(0..nodes.len())];
dbg!(&source);
dbg!(&dest);
//io::stdin().read_line(&mut input).expect("Failed to read input");
if source == dest {
println!("0");
continue 'question;
}
if source.0 == dest.0 || source.1 == dest.1 {
println!("1");
continue 'question;
}
let mut distancehash: HashMap<usize, usize> = HashMap::new();
distancehash.insert(source.0, 0);
let mut queue: VecDeque<usize> = VecDeque::new();
queue.push_front(source.0);
for neighborrow in colgrid[source.1].iter() {
if *neighborrow != source.0 {
if *neighborrow == dest.0 {
println!("2");
continue 'question;
}
distancehash.insert(*neighborrow, 1);
queue.push_front(*neighborrow);
}
}
while queue.len() != 0 {
let row = queue.pop_back().unwrap();
let dist = *distancehash.get(&row).unwrap();
let neighborrows = &rowtorow[&row];
dbg!(&rowtorow);
for neighborrow in neighborrows.iter() {
if *neighborrow == dest.0 {
if colgrid[dest.1].contains(&row) {
println!("{}", dist+2);
continue 'question;
} else {
println!("{}", dist+3);
continue 'question;
}
}
match distancehash.get(&neighborrow) {
Some(_) => {}
None => {
distancehash.insert(*neighborrow, dist+2);
queue.push_front(*neighborrow);
}
}
}
}
println!("-1");
};
}