include <stdio.h>

include <math.h>

int main() {

double a, b, c, d, e, h, f = 0;
scanf("%lf %lf %lf %lf %lf", &a, &b, &c, &d, &e);
a = ceil(a);

if (a <= 1) {

	f = f + 5;
} else {

	f = f + 5 + (a - 1) * 0.5;
}

b = ceil(b);

if (b <= 100) {

	f = f + 5;
} else {

	f = f + 5 + (b - 100) * 0.15;
}

h = (c * d * e) / 6000;
int t = h / 10;

if (h <= 10) {

	f = f + 0;
} else {

	f = f + 0 + (t - 1);
}

printf("%.2lf", f);
return 0;

}