Problem Statement

There are $N$ cities and $M$ roads in the Kingdom of Takahashi.

The cities are numbered $1$ through $N$, and the roads are numbered $1$ through $M$. Road $i$ is a one-way road that leads from City $A_i$ to City $B_i$, and it takes $C_i$ minutes to go through it.

Let us define $f(s, t, k)$ as the answer to the following query.

• Compute the minimum time needed to get from City $s$ to City $t$. Here, other than the Cities $s$ and $t$, it is only allowed to pass through Cities $1$ through $k$. If City $t$ is unreachable or $s = t$, the answer should be $0$.

Compute $f(s,t,k)$ for all triples $s,t,k$ and print the sum of them. More formally, print $\displaystyle \sum_{s = 1}^N \sum_{t = 1}^N \sum_{k = 1}^N f(s, t, k)$.

Constraints

• $1 \leq N \leq 400$
• $0 \leq M \leq N(N-1)$
• $1 \leq A_i \leq N$ $(1 \leq i \leq M)$
• $1 \leq B_i \leq N$ $(1 \leq i \leq M)$
• $A_i \neq B_i$ $(1 \leq i \leq M)$
• $1 \leq C_i \leq 10^6$ $(1 \leq i \leq M)$
• $A_i \neq A_j$ or $B_i \neq B_j$, if $i \neq j$.
• All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M
A_1 B_1 C_1
\vdots
A_M B_M C_M

Output

Print $\displaystyle \sum_{s = 1}^N \sum_{t = 1}^N \sum_{k = 1}^N f(s, t, k)$.