Codeforces 40-C

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

int main()
{
        string input;
        cin>>input;
        string made=input.substr(0,1);
        bool at=false;
        for(int i=1;i<input.length();)
        {
                if(input.substr(i,3)=="dot"&&i+3!=input.length())
                        {
                                made=made+".";
                                i+=3;
                        }
                else if(input.substr(i,2)=="at"&&at==false&&i+2!=input.length())
                {
                        at=true;
                        made=made+"@";
                        i+=2;
                }
                else
                {
                        made=made+input.substr(i,1);
                        i++;
                }
        }
        cout<<made<<endl;
        return 0;
}