int main(){
    int n;
    cin>>n;
    vi t;
    t.resize(n,-1);
    dp.resize(n,t);              // dp is n X n
    for(int i=0;i<n;i++){
            int r,c;
            cin>>r>>c;
            vi temp;
            temp.pb(r);
            temp.pb(c);
            matrices.pb(temp);
            }
    cout<<solve(0,n-1)<<endl;
    int A;
    cin>>A;
    return 0;
}