#include <stdio.h>
int main()
{
double a,b;
char op;
scanf("%lf%c%lf",&a,&op,&b);
if ('+' == op)
printf("%.2lf",a+b);
else if('-' == op)
printf("%.2lf",a-b);
else if('*' == op)
printf("%.2lf",a*b);
else if('/' == op)
{
if(b == 0)
printf("divisorerror");
else
printf("%.2lf",a/b);
}
return 0;
}