#include<fstream.h>
ifstream f("fractii.in");
ofstream g("fractii.out");
int main()
{int n,i,j,nr;
f>>n;
i=1;j=0;nr=0;
while(nr<n)
{	for(j=1;j<=4&&nr<=n;j++)
	{x=i;y=j;
	while(x!=y)if(x>y)x=x-y;
		else if(y>x)y=y-x;
	if(y==1)nr++;
	}
i++;
}