#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:60000000")
using namespace std;
const long double eps = 1e-9;
const int inf = (1 << 30) - 1;
const long long inf64 = ((long long)1 << 62) - 1;
const long double pi = 3.1415926535897932384626433832795;
template <class T>
T sqr(T x) {
  return x * x;
}
int n;
double a, d;
int main() {
  cin >> n >> a >> d;
  double max_t = 0;
  for (int i = 0; i < (int)(n); i++) {
    double t, v;
    scanf("%lf%lf", &t, &v);
    double tm;
    if (v * v / a / 2. >= d)
      tm = sqrt(2 * d / a);
    else
      tm = v / a + (d - (v * v / a / 2.)) / v;
    tm += t;
    if (tm <= max_t) tm = max_t;
    max_t = tm;
    printf("%.10lf\n", max_t);
  }
  return 0;
}
