baca

n = "bac10" #change name for each test case
inp = n + ".in"
outp = n + ".out"
f = open(inp, 'r')
x = f.read()
y = int(x)
f.close()
z = y // 4
s = str(z)
o = open(outp, 'w')
o.write(s)
o.close()