n = int(input())
t = []
for i in range(1, n + 1):
    for j in range(1, i + 1):
        t.append(i)
print(t[n - 1])
/**************************************************************
	Problem: 1248
	User: admin
	Language: Python
	Result: Accepted
	Time:92 ms
	Memory:34244 kb
****************************************************************/