#include<stdio.h>
int main()
{
float a;
float c;
char b;
scanf("%f%c%f",&a,&b,&c);
if(b=='+')
printf("%.2f\n",a+c);
else if(b=='-')
printf("%.2f\n",a-c);
else if(b=='*')
printf("%.2f\n",a*c);
else if(b=='/')
{
if(c!=0.)
printf("%.2f\n",a/c);
else
printf("除数为零\n");
}else{
printf("%Error!");
}
return 0;
}