#include <bits/stdc++.h>
using namespace std;
int n, a, d, t, v, i;
double y = -1, x;
int main() {
  scanf("%d%d%d", &n, &a, &d);
  for (i = 0; i < n; ++i) {
    scanf("%d%d", &t, &v);
    if (2ll * d * a > (long long)v * v) {
      x = v * 0.5 / a + d * 1.0 / v;
    } else
      x = sqrt(d * 2.0 / a);
    x += t;
    if (x > y) y = x;
    printf("%.12lf\n", y);
  }
  return 0;
}
