#include<iostream.h>
#include<fstream.h>
int main()
{long P,Q,N,T,D,C;
int R;
fstream f("fractii.in",ios::in),g("fractii.out",ios::out);
f>>N;
P=1;
Q=2;
T=1;
D=2;
R=1;
while (P<=N)
{if (Q>P)
C=Q;
else
	C=P;
while (D<=C)
	{if (Q%D==0)
	{if (P%D==0)
		{R=3;
		D=C;
		}
	}
	D=D+1;
	}
	if (R==1)
	T=T+1;
	D=2;
	R=1;
Q=Q+1;
if (Q>N)
{P=P+1;
Q=1;
}
}
g<<T;
}