#include <bits/stdc++.h>
#pragma comment(linker, "/stack:64000000")
using namespace std;
template <typename X>
inline X abs(const X& a) {
  return a < 0 ? -a : a;
}
template <typename X>
inline X sqr(const X& a) {
  return a * a;
}
const int INF = INT_MAX / 2;
const long long INF64 = LLONG_MAX / 2LL;
const long double EPS = 1E-9, PI = 3.1415926535897932384626433832795;
int main() {
  int n;
  long double a, d;
  cin >> n >> a >> d;
  long double prev = 0.0;
  for (int i = 0; i < int(n); i++) {
    long double t, v;
    int x, y;
    scanf("%d%d", &x, &y);
    t = x, v = y;
    long double cur = min(sqrt(2.0 * d / a), v / a);
    long double rem = d - a * sqr(cur) / 2.0;
    cur += rem / v;
    cur += t;
    cur = max(cur, prev);
    printf("%.10lf\n", double(cur));
    prev = max(prev, cur);
  }
  return 0;
}
