fin = open("fact.in","r")
fout = open("fact.out","w")
p = int(fin.read())
n = 1
fac = 1
ok = False

while(ok == False or n == -1):
    fac = fac * (n+1)
    n+= 1
    if (10**p) != 1:
        if fac % (10**p) == 0:
            ok = True
        else:
            n = -1
    else:
        n = 1
        ok = True
        
n = str(n)
fout.write(n)
fin.close()
fout.close()