from math import gcd
a, b, c, d, e = map(int, input().split())
f = (a+b)*(c+d)//gcd(a+b, c+d)
mk = f//(a+b)
ff = lambda k:(k*(a+b))%(c+d) if (k*(a+b))%(c+d) else c+d
R = 0
xx = e%f//(a+b)
rr = 0
fl=0
for k in range(mk):
    nokori = min(max(c-ff(k), 0), a)
    if a-(c+d-ff(k)) >=0:
        ek, fk = divmod(a-(c+d-ff(k)), c+d)
        r = min(fk,c)+ek*c + nokori
    else:
        r = nokori
    if k==xx:
        ta = min(a, e%(a+b))
        nokori = min(max(c-ff(k), 0), ta)
        if ta-(c+d-ff(k)) >=0:
            ek, fk = divmod(ta-(c+d-ff(k)), c+d)
            rr += min(fk,c)+ek*c + nokori
        else:
            rr += max(0, nokori)
        fl = 1
    if not fl:
        rr += r
#        print("xx",r)
    R += r
#    print(mk, r, rr)
#print(R, rr, e//f)
print(R*(e//f)+rr)