3. The 2008 Olympic Games will be held in Beijing. Figure 3 is the Olympic five-ring logo, where $a, b, c, d, e, g, h, i$ are filled with different numbers from $1 \sim 9$. If the sum of the numbers in each circle is equal, then the maximum value of this sum is $\qquad$


3.14 .

Let the sum of the numbers in each circle be $N$, then
$$
(1+2+\cdots+9)+(b+d+f+h)=5 N .
$$

Therefore, $N=\frac{b+d+f+h}{5}+9$.
To maximize $N$, $b+d+f+h$ must be the largest possible value and a multiple of 5.

Since $b+d+f+h=6+7+8+9=30$ is the maximum, and $N=15$, at this point, no matter how you fill in the numbers, there will be repeated or missing numbers. Therefore, $N$ cannot exceed 14.

After testing, when $a=5, b=9, c=2, d=3, e=4, f=7$, $g=1, h=6, i=8$, the conditions of the problem are satisfied.
Thus, the maximum sum of the numbers is 14.