#include <bits/stdc++.h>
using namespace std;
#define int long long
int depth(int x) {
if ((int)(pow(8*x+1, 0.5)+1)/2 == (pow(8*x+1, 0.5)+1)/2) return (pow(8*x+1, 0.5)+1)/2-1;
else return (int)(pow(8*x+1, 0.5)+1)/2;
}
signed main() {
int n; cin >> n;
int q; cin >> q;
int t; cin >> t;
int a[n+1];
for (int i = 1; i < n+1; i++) {
int x; cin >> x;
a[i] = x-((i-1)*i)/2;
}
while (q--) {
int x, y; cin >> x >> y;
//first check for depth
if (y > x) swap(x, y);
while (depth(x) != depth(y)) {
//set x to its parent
int tmp = depth(x);
if (x-((tmp-1)*tmp)/2 > a[tmp-1]) x--;
x -= (tmp-1);
}
while (x != y) {
//set it to its parent
int tmp = depth(x);
if (x-((tmp-1)*tmp)/2 > a[tmp-1]) x--;
x -= (tmp-1);
if (y-((tmp-1)*tmp)/2 > a[tmp-1]) y--;
y -= (tmp-1);
}
cout << x << '\n';
}
}
