+23 For integers $a$ and $T$, $T \neq 0,$ a parabola whose general equation is $y = ax^2 + bx + c$ passes through the points $A = (0,0),$, $B = (2T,0)$, $C = (2T + 1,28).$ and $N$ Let be the sum of the coordinates of the vertex point. Determine the largest value of $N$
