#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using pl = pair<ll, ll>;
using pi = pair<int, int>;
using vpl = vector<pl>;
using vpi = vector<pi>;
using vc = vector<char>;
using vs = vector<string>;
#define forn(i, n) for(int i = 0; i < n; i++)
#define rofn(i, n) for(int i = n; i >= 0; i--)
#define FOR(i, a, b) for(int i = a; i < b; i++)
#define ROF(i, b, a) for(int i = b; i >= a; i--)
#define TRAV(a, x) for(auto& a: x)
#define ABC(c) for(char c = 'a'; c <= 'z'; c++)
#define all(x) begin(x), end(x)
#define sor(x) sort(all(x))
#define rsor(x) sort(all(x), greater<int>())
#define pb push_back
#define mp make_pair
#define ins insert
#define ub upper_bound
#define lb lower_bound
#define len(x) (int)(x).length()
#define sz(x) (int)(x).size()
#define f first
#define s second
#define dbg(x) TRAV(a, x) cout << a << " "
#define print(x) cout << x << endl
#define traverse(x) TRAV(a, x) cout << a.f << " " << a.s << endl
#define readvi(a, n) forn(i, n) cin >> a[i]
#define readvpi(a, n) forn(i, n) cin >> a[i].f >> a[i].s
#define gcd(a, b) __gcd(a, b)
double cost(double x1, double r1, double x2){
return ((x1 - x2) * (x1 - x2)) / ((4 * r1));
}
void solve(){
int n; cin >> n;
stack<pair<double, double>> st;
forn(i, n){
double x, r; cin >> x >> r;
double res = r;
while(!st.empty()){
res = min(res, cost(st.top().f, st.top().s, x));
if(res >= st.top().s) st.pop();
else break;
}
cout << fixed << setprecision(3) << res << endl;
st.push({x, res});
}
}
int main(){
ios::sync_with_stdio(0); cin.tie(0);
// int t; cin >> t;
// forn(i, t){
// solve();
// }
solve();
}
