#include <stdio.h>
#include <math.h>
int main(){
	int x, i=1;
	scanf("%d",&x);
	double factorial=1, sum=1;
	if(x==0)	
		printf("%f",sum);
	else{
		while(i <= 1024){
			factorial *= i;
			sum += pow(x,i)/factorial;
			i++;
		}
		printf("%f",sum);
	}
	return 0;
}