#include <bits/stdc++.h>

#define NS (10000005)

using namespace std;

int n, A, B, C, a[NS];

double ans;

int main(int argc, char const* argv[])
{
    scanf("%d%d%d%d%d", &n, &A, &B, &C, a + 1);
    for (int i = 2; i <= n; i += 1) a[i] = (1ll * a[i-1] * A + B) % 100000001;
    for (int i = 1; i <= n; i += 1) a[i] = a[i] % C + 1;
    ans = (double)min(a[1], a[n]) / a[1] / a[n];
    for (int i = 2; i <= n; i += 1)
        ans += (double)min(a[i], a[i - 1]) / a[i] / a[i - 1];
    printf("%.3f\n", ans);
    return 0;
}