poj 3117 World Cup

#include<iostream>        //比赛场数乘3减去分数之和
#include<string>
using namespace std;
int main()
{
int t,n,a,s;
string str;
while(cin>>t>>n,t)
    {
        s=0;
while(t--)
        {
            cin>>str>>a;
            s+=a;
        }
        cout<<3*n-s<<endl;
    }
return 0;
}