Danov1802 27.1

#include <iostream>

using namespace std;

int main(){
    int n;
    cin>>n;

    int a, b, c;
    cin>>a>>b>>c;

    for(int i=1;i<n;i++){
        int k1, k2, k3;
        cin>>k1>>k2>>k3;

        int a1, b1, c1;
        a1=max(a+k1, max(b+k1, c+k1));
        c1=max(a+k3, max(b+k3, c+k3));
        b1=max(a+k2, c+k2);

        a=a1;
        b=b1;
        c=c1;
    }

    cout<<max(a, max(b,c));
}