#include <stdio.h>
#include <stdlib.h>

long int n, a, b, c, i;
long int pv[1000000][4];

long int Greater(long int a, long int b)
{
    return (a > b) ? a : b;
}

int main()
{
    scanf("%ld", &n);
    if (n==0)
        printf("0");
    else
    {
        for (i = 0; i<n; i++)
        {
            scanf("%ld%ld%ld", &a, &b, &c);
            if (i==0)
            {
                pv[i][0] = 0;
                pv[i][1] = a;
                pv[i][2] = b;
                pv[i][3] = -9999999;
            }
            else
            {
                pv[i][0] = Greater(pv[i-1][0], pv[i-1][1]);
                pv[i][1] = Greater(pv[i-1][0]+a, a);
                pv[i][2] = Greater(pv[i-1][2], pv[i-1][3]) + b;
                pv[i][3] = Greater(pv[i-1][2], pv[i-1][3]) + c;
            }
        }
        a = (n > 1) ? Greater(pv[n-1][0], Greater(pv[n-1][1], pv[n-1][2])) : Greater(pv[n-1][0], pv[n-1][1]);
        printf("%ld", a);
    }
    return 0;
}