#include<iostream>
using namespace std;
int main()
{
    string name;
    float wei,pri;
    cin>>name;
    if(name!="fruit" || name!="vegetable")
    {
        cout<<"Invalid input"
    }
    else
    {
        cin>>wei>>pri;
        if(wei>=0.1 && wei<=100 && pri>=0.5 && pri<=200)
        {
            cout<<wei*pri;
        }
        else
        {
            cout<<"Invalid input";
        }
    }
    return 0;
}