#include
int main()
{
float num,r;
char op;
scanf("%f,%c,%f",&r,&op,&num);
switch(op)
{
case '+':
r+=num;
break;
case '-':
r-=num;
break;
case '*':
r*=num;
break;
case '/':
if(0==num)
{
puts("Error");
return 0;
}
r/=num;
break;
default:
puts("Error");
return 0;
}
printf("%.1f\n",r);
return 0;
}