#include <iostream>
#include <stack>
using namespace std;

stack<long long> number;

int main()
{
    long long temp=0;char ch;
    bool flag=false;
    while( ( ch=getchar() )!='\n')
    {
        if(flag && ch>='0' && ch<='9' )
        {
            temp*=10;temp+=ch-'0';continue;
        }
        if(ch=='.')
        {
            number.push(temp);flag=false;temp=0;
            continue;
        }
        else if(ch>='0' && ch<='9')
        {
            temp=ch-'0';flag=true;
            continue;
        }
        else if(ch=='@')
            cout<<number.top();
        else
        {
            int A=number.top(); number.pop();//删去该pop语句和下面的pop语句会出现五个TLE
            int B=number.top(); number.pop();

            switch(ch)
            {
                case '*': 
                    number.push(A*B);break;
                case '/': 
                    number.push(B/A);break;
                case '+': 
                    number.push(A+B);break;
                case '-':  
                    number.push(B-A);break;
            }
        }

    }

    return 0;
}