#include
int jiecheng(int a);
int cifang(int b,int c);
int main(void)
{
int x,f=1,c=3;//f为符号和阶乘的数字(单数为负号)。c为左下的乘数和次方数。
double sum=0.0;
scanf("%d",&x);
sum=(double)x;
do{
if(f%2==0){
sum+=1.0*cifang(x,c)/(c*jiecheng(f));
} else {
sum-=1.0*cifang(x,c)/(c*jiecheng(f));
}
c+=2;
f+=1;
}while(f<10);
printf("%.6f",sum);
return 0;
}
int jiecheng(int a)
{
int i,n=1;
for(i=1;i<=a;i++){
n*=i;
}
return n;
}
int cifang(int b,int c)
{
int i;
for(i=0;i<c;i++){
b*=b;
}
return b;
}