#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <map>
#include <set>
#include <climits>
#include <cmath>
#include <fstream>
#include <queue>
using namespace std;
const int MAXN = 1e5+5;
struct state {
int a;
int b;
int idx;
};
int sz[MAXN], par[MAXN];
vector<state> queries[MAXN];
int get(int x) {
return x == par[x] ? x : par[x] = get(par[x]);
}
void unite(int a, int b) {
a = get(a), b = get(b);
if (a == b) {
return;
}
if (sz[a] > sz[b]) {
swap(a, b);
}
par[a] = b;
for (auto i : queries[a]) {
queries[b].push_back(i);
}
sz[b] += sz[a];
}
int main() {
int n, m, q;
cin >> n >> m >> q;
int ans[MAXN];
for (int i = 0; i < MAXN; i++) {
sz[i] = 1;
par[i] = i;
ans[i] = -1;
}
for (int i = 0; i < q; i++) {
int a, b;
cin >> a >> b;
queries[a].push_back({ a, b, i });
queries[b].push_back({ a, b, i });
}
for (int i = 0; i < m; i++) {
for (int j = m - i; j <= n; j += (m - i)) {
unite(m - i, j);
for (auto k : queries[get(j)]) {
if (ans[k.idx] != -1) {
continue;
}
if (get(k.a) == get(k.b)) {
ans[k.idx] = i + 1;
}
}
}
}
for (int i = 0; i < q; i++) {
cout << ans[i] << endl;
}
}
