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

    int n;
    int a[1100],dp[1100];

    int main(){
        cin>>n;
        for(int i=1;i<=n;i++){
            cin>>a[i];
            dp[i]={{ input(1) }};
            for(int j=1;j<i;j++){
                 if({{ input(2) }}){
                     dp[i]=max({{ input(3) }},dp[i]);
                 }
            }
        }
        cout<<*max_element(dp+1,dp+1+n);
        return 0;
    }