#include <bits/stdc++.h>
using namespace std;
const long double eps = 1e-10;
inline long double solve(long double v, long double a, long double d) {
  long double t = v / a;
  if (v * t / 2 + eps >= d) return sqrt(2 * d / a);
  d -= t * v / 2;
  return t + d / v;
}
int main() {
  ios_base::sync_with_stdio(false);
  int n, a, d;
  cin >> n >> a >> d;
  long double prev = -1;
  for (int cnt = 0; cnt < (n); cnt++) {
    int t, v;
    cin >> t >> v;
    long double cur = solve(v, a, d);
    cur = max(cur + t, prev);
    cout << fixed << setprecision(10) << cur << '\n';
    prev = cur;
  }
  return 0;
}
