/*#include <stdio.h>
int main(){
int a,b;
scanf("%d %d",&a,&b);
printf("%d+%d=%d\n",a,b,a+b);
printf("%d-%d=%d\n",a,b,a-b);
printf("%d*%d=%d\n",a,b,a*b);
printf("%d/%d=%d",a,b,a/b);
return 0;
}
#include <stdio.h>
int main(){
int a,b;
scanf("%d %d",&a,&b);
printf("%.1f",(double)a*b/2);
return 0;
}*/
#include <stdio.h>
int main() {
int a;
scanf("%d",&a);
printf("%.3f",(double)9/5*a+32);
return 0;
}