#include <bits/stdc++.h>
using namespace std;
const int INF = 1000000000;
const int N = 207;
int main() {
  const long double eps = 1e-7;
  int n;
  long double a, d;
  cin >> n >> a >> d;
  long double prv = -1e18;
  for (int i = 0; i < n; ++i) {
    long long t, v;
    cin >> t >> v;
    long double acTime = v / a;
    long double cur;
    if (a * acTime * acTime / 2.0 > d - eps)
      cur = sqrtl(2.0 * d / a);
    else
      cur = acTime + (d - a * acTime * acTime / 2.0) / v;
    cur += t;
    cur = max(cur, prv);
    printf("%.9lf\n", (double)cur);
    prv = cur;
  }
  return 0;
}
