meetforever/GRPO_CL huggingface dataset:
user: You are the top spy of AtCoder Kingdom. To prevent the stolen secret from being handed to AlDebaran Kingdom, you have sneaked into the party where the transaction happens.
There are N attendees in the party, and they are given attendee numbers from 1 through N. The height of Attendee i is A_i.
According to an examination beforehand, you know that a pair of attendees satisfying the condition below will make the transaction.
 - The absolute difference of their attendee numbers is equal to the sum of their heights.
There are \frac{N(N-1)}{2} ways to choose two from the N attendees and make a pair. Among them, how many satisfy the condition above?
P.S.: We cannot let you know the secret.

-----Constraints-----
 - All values in input are integers.
 - 2 \leq N \leq 2 \times 10^5
 - 1 \leq A_i \leq 10^9\ (1 \leq i \leq N)

-----Input-----
Input is given from Standard Input in the following format:
N
A_1 A_2 \dots A_N

-----Output-----
Print the number of pairs satisfying the condition.

-----Sample Input-----
6
2 3 3 1 3 1

-----Sample Output-----
3

 - A_1 + A_4 = 3, so the pair of Attendee 1 and 4 satisfy the condition.
 - A_2 + A_6 = 4, so the pair of Attendee 2 and 6 satisfy the condition.
 - A_4 + A_6 = 2, so the pair of Attendee 4 and 6 satisfy the condition.
No other pair satisfies the condition, so you should print 3.
user: Given are two strings s and t consisting of lowercase English letters. Determine if the number of non-negative integers i satisfying the following condition is finite, and find the maximum value of such i if the number is finite.
 - There exists a non-negative integer j such that the concatenation of i copies of t is a substring of the concatenation of j copies of s.

-----Notes-----
 - A string a is a substring of another string b if and only if there exists an integer x (0 \leq x \leq |b| - |a|) such that, for any y (1 \leq y \leq |a|), a_y = b_{x+y} holds.
 - We assume that the concatenation of zero copies of any string is the empty string. From the definition above, the empty string is a substring of any string. Thus, for any two strings s and t, i = 0 satisfies the condition in the problem statement.

-----Constraints-----
 - 1 \leq |s| \leq 5 \times 10^5
 - 1 \leq |t| \leq 5 \times 10^5
 - s and t consist of lowercase English letters.

-----Input-----
Input is given from Standard Input in the following format:
s
t

-----Output-----
If the number of non-negative integers i satisfying the following condition is finite, print the maximum value of such i; if the number is infinite, print -1.

-----Sample Input-----
abcabab
ab

-----Sample Output-----
3

The concatenation of three copies of t, ababab, is a substring of the concatenation of two copies of s, abcabababcabab, so i = 3 satisfies the condition.
On the other hand, the concatenation of four copies of t, abababab, is not a substring of the concatenation of any number of copies of s, so i = 4 does not satisfy the condition.
Similarly, any integer greater than 4 does not satisfy the condition, either. Thus, the number of non-negative integers i satisfying the condition is finite, and the maximum value of such i is 3.
user: AtCoDeer is thinking of painting an infinite two-dimensional grid in a checked pattern of side K.
Here, a checked pattern of side K is a pattern where each square is painted black or white so that each connected component of each color is a K × K square.
Below is an example of a checked pattern of side 3:
AtCoDeer has N desires.
The i-th desire is represented by x_i, y_i and c_i.
If c_i is B, it means that he wants to paint the square (x_i,y_i) black; if c_i is W, he wants to paint the square (x_i,y_i) white.
At most how many desires can he satisfy at the same time?

-----Constraints-----
 - 1 ≤ N ≤ 10^5
 - 1 ≤ K ≤ 1000
 - 0 ≤ x_i ≤ 10^9
 - 0 ≤ y_i ≤ 10^9
 - If i ≠ j, then (x_i,y_i) ≠ (x_j,y_j).
 - c_i is B or W.
 - N, K, x_i and y_i are integers.

-----Input-----
Input is given from Standard Input in the following format:
N K
x_1 y_1 c_1
x_2 y_2 c_2
:
x_N y_N c_N

-----Output-----
Print the maximum number of desires that can be satisfied at the same time.

-----Sample Input-----
4 3
0 1 W
1 2 W
5 3 B
5 4 B

-----Sample Output-----
4

He can satisfy all his desires by painting as shown in the example above.
user: There are N towns numbered 1 to N and M roads. The i-th road connects Town A_i and Town B_i bidirectionally and has a length of C_i.
Takahashi will travel between these towns by car, passing through these roads. The fuel tank of his car can contain at most L liters of fuel, and one liter of fuel is consumed for each unit distance traveled. When visiting a town while traveling, he can full the tank (or choose not to do so). Travel that results in the tank becoming empty halfway on the road cannot be done.
Process the following Q queries:
 - The tank is now full. Find the minimum number of times he needs to full his tank while traveling from Town s_i to Town t_i. If Town t_i is unreachable, print -1.

-----Constraints-----
 - All values in input are integers.
 - 2 \leq N \leq 300
 - 0 \leq M \leq \frac{N(N-1)}{2}
 - 1 \leq L \leq 10^9
 - 1 \leq A_i, B_i \leq N
 - A_i \neq B_i
 - \left(A_i, B_i\right) \neq \left(A_j, B_j\right) (if i \neq j)
 - \left(A_i, B_i\right) \neq \left(B_j, A_j\right) (if i \neq j)
 - 1 \leq C_i \leq 10^9
 - 1 \leq Q \leq N\left(N-1\right)
 - 1 \leq s_i, t_i \leq N
 - s_i \neq t_i
 - \left(s_i, t_i\right) \neq \left(s_j, t_j\right) (if i \neq j)

-----Input-----
Input is given from Standard Input in the following format:
N M L
A_1 B_1 C_1
:
A_M B_M C_M
Q
s_1 t_1
:
s_Q t_Q

-----Output-----
Print Q lines.
The i-th line should contain the minimum number of times the tank needs to be fulled while traveling from Town s_i to Town t_i. If Town t_i is unreachable, the line should contain -1 instead.

-----Sample Input-----
3 2 5
1 2 3
2 3 3
2
3 2
1 3

-----Sample Output-----
0
1

To travel from Town 3 to Town 2, we can use the second road to reach Town 2 without fueling the tank on the way.
To travel from Town 1 to Town 3, we can first use the first road to get to Town 2, full the tank, and use the second road to reach Town 3.
user: We have a set S of N points in a two-dimensional plane. The coordinates of the i-th point are (x_i, y_i). The N points have distinct x-coordinates and distinct y-coordinates.
For a non-empty subset T of S, let f(T) be the number of points contained in the smallest rectangle, whose sides are parallel to the coordinate axes, that contains all the points in T. More formally, we define f(T) as follows:
 - f(T) :=  (the number of integers i (1 \leq i \leq N) such that a \leq x_i \leq b and c \leq y_i \leq d, where a, b, c, and d are the minimum x-coordinate, the maximum x-coordinate, the minimum y-coordinate, and the maximum y-coordinate of the points in T)
Find the sum of f(T) over all non-empty subset T of S. Since it can be enormous, print the sum modulo 998244353.

-----Constraints-----
 - 1 \leq N \leq 2 \times 10^5
 - -10^9 \leq x_i, y_i \leq 10^9
 - x_i \neq x_j (i \neq j)
 - y_i \neq y_j (i \neq j)
 - All values in input are integers.

-----Input-----
Input is given from Standard Input in the following format:
N
x_1 y_1
:
x_N y_N

-----Output-----
Print the sum of f(T) over all non-empty subset T of S, modulo 998244353.

-----Sample Input-----
3
-1 3
2 1
3 -2

-----Sample Output-----
13

Let the first, second, and third points be P_1, P_2, and P_3, respectively. S = \{P_1, P_2, P_3\} has seven non-empty subsets, and f has the following values for each of them:
 - f(\{P_1\}) = 1
 - f(\{P_2\}) = 1
 - f(\{P_3\}) = 1
 - f(\{P_1, P_2\}) = 2
 - f(\{P_2, P_3\}) = 2
 - f(\{P_3, P_1\}) = 3
 - f(\{P_1, P_2, P_3\}) = 3
The sum of these is 13.
user: Takahashi has come to a party as a special guest.
There are N ordinary guests at the party. The i-th ordinary guest has a power of A_i.
Takahashi has decided to perform M handshakes to increase the happiness of the party (let the current happiness be 0).
A handshake will be performed as follows:
 - Takahashi chooses one (ordinary) guest x for his left hand and another guest y for his right hand (x and y can be the same).
 - Then, he shakes the left hand of Guest x and the right hand of Guest y simultaneously to increase the happiness by A_x+A_y.
However, Takahashi should not perform the same handshake more than once. Formally, the following condition must hold:
 - Assume that, in the k-th handshake, Takahashi shakes the left hand of Guest x_k and the right hand of Guest y_k. Then, there is no pair p, q (1 \leq p < q \leq M) such that (x_p,y_p)=(x_q,y_q).
What is the maximum possible happiness after M handshakes?

-----Constraints-----
 - 1 \leq N \leq 10^5
 - 1 \leq M \leq N^2
 - 1 \leq A_i \leq 10^5
 - All values in input are integers.

-----Input-----
Input is given from Standard Input in the following format:
N M
A_1 A_2 ... A_N

-----Output-----
Print the maximum possible happiness after M handshakes.

-----Sample Input-----
5 3
10 14 19 34 33

-----Sample Output-----
202

Let us say that Takahashi performs the following handshakes:
 - In the first handshake, Takahashi shakes the left hand of Guest 4 and the right hand of Guest 4.
 - In the second handshake, Takahashi shakes the left hand of Guest 4 and the right hand of Guest 5.
 - In the third handshake, Takahashi shakes the left hand of Guest 5 and the right hand of Guest 4.
Then, we will have the happiness of (34+34)+(34+33)+(33+34)=202.
We cannot achieve the happiness of 203 or greater, so the answer is 202.
user: Takahashi will take part in an eating contest. Teams of N members will compete in this contest, and Takahashi's team consists of N players numbered 1 through N from youngest to oldest. The consumption coefficient of Member i is A_i.
In the contest, N foods numbered 1 through N will be presented, and the difficulty of Food i is F_i. The details of the contest are as follows:
 - A team should assign one member to each food, and should not assign the same member to multiple foods.
 - It will take x \times y seconds for a member to finish the food, where x is the consumption coefficient of the member and y is the difficulty of the dish.
 - The score of a team is the longest time it takes for an individual member to finish the food.
Before the contest, Takahashi's team decided to do some training. In one set of training, a member can reduce his/her consumption coefficient by 1, as long as it does not go below 0. However, for financial reasons, the N members can do at most K sets of training in total.
What is the minimum possible score of the team, achieved by choosing the amounts of members' training and allocating the dishes optimally?

-----Constraints-----
 - All values in input are integers.
 - 1 \leq N \leq 2 \times 10^5
 - 0 \leq K \leq 10^{18}
 - 1 \leq A_i \leq 10^6\ (1 \leq i \leq N)
 - 1 \leq F_i \leq 10^6\ (1 \leq i \leq N)

-----Input-----
Input is given from Standard Input in the following format:
N K
A_1 A_2 ... A_N
F_1 F_2 ... F_N

-----Output-----
Print the minimum possible score of the team.

-----Sample Input-----
3 5
4 2 1
2 3 1

-----Sample Output-----
2

They can achieve the score of 2, as follows:
 - Member 1 does 4 sets of training and eats Food 2 in (4-4) \times 3 = 0 seconds.
 - Member 2 does 1 set of training and eats Food 3 in (2-1) \times 1 = 1 second.
 - Member 3 does 0 sets of training and eats Food 1 in (1-0) \times 2 = 2 seconds.
They cannot achieve a score of less than 2, so the answer is 2.
user: Snuke, a water strider, lives in a rectangular pond that can be seen as a grid with H east-west rows and W north-south columns. Let (i,j) be the square at the i-th row from the north and j-th column from the west.
Some of the squares have a lotus leaf on it and cannot be entered.
The square (i,j) has a lotus leaf on it if c_{ij} is @, and it does not if c_{ij} is ..
In one stroke, Snuke can move between 1 and K squares (inclusive) toward one of the four directions: north, east, south, and west.
The move may not pass through a square with a lotus leaf. Moving to such a square or out of the pond is also forbidden.
Find the minimum number of strokes Snuke takes to travel from the square (x_1,y_1) to (x_2,y_2).
If the travel from (x_1,y_1) to (x_2,y_2) is impossible, point out that fact.

-----Constraints-----
 - 1 \leq H,W,K \leq 10^6
 - H \times W \leq 10^6
 - 1 \leq x_1,x_2 \leq H
 - 1 \leq y_1,y_2 \leq W
 - x_1 \neq x_2 or y_1 \neq y_2.
 - c_{i,j} is . or @.
 - c_{x_1,y_1} = .
 - c_{x_2,y_2} = .
 - All numbers in input are integers.

-----Input-----
Input is given from Standard Input in the following format:
H W K
x_1 y_1 x_2 y_2
c_{1,1}c_{1,2} .. c_{1,W}
c_{2,1}c_{2,2} .. c_{2,W}
:
c_{H,1}c_{H,2} .. c_{H,W}

-----Output-----
Print the minimum number of strokes Snuke takes to travel from the square (x_1,y_1) to (x_2,y_2), or print -1 if the travel is impossible.

-----Sample Input-----
3 5 2
3 2 3 4
.....
.@..@
..@..

-----Sample Output-----
5

Initially, Snuke is at the square (3,2).
He can reach the square (3, 4) by making five strokes as follows:
 - From (3, 2), go west one square to (3, 1).
 - From (3, 1), go north two squares to (1, 1).
 - From (1, 1), go east two squares to (1, 3).
 - From (1, 3), go east one square to (1, 4).
 - From (1, 4), go south two squares to (3, 4).
user: Takahashi had a pair of two positive integers not exceeding N, (a,b), which he has forgotten.
He remembers that the remainder of a divided by b was greater than or equal to K.
Find the number of possible pairs that he may have had.

-----Constraints-----
 - 1 \leq N \leq 10^5
 - 0 \leq K \leq N-1
 - All input values are integers.

-----Input-----
Input is given from Standard Input in the following format:
N K

-----Output-----
Print the number of possible pairs that he may have had.

-----Sample Input-----
5 2

-----Sample Output-----
7

There are seven possible pairs: (2,3),(5,3),(2,4),(3,4),(2,5),(3,5) and (4,5).
user: There are N persons called Person 1 through Person N.
You are given M facts that "Person A_i and Person B_i are friends." The same fact may be given multiple times.
If X and Y are friends, and Y and Z are friends, then X and Z are also friends. There is no friendship that cannot be derived from the M given facts.
Takahashi the evil wants to divide the N persons into some number of groups so that every person has no friend in his/her group.
At least how many groups does he need to make?

-----Constraints-----
 - 2 \leq N \leq 2\times 10^5
 - 0 \leq M \leq 2\times 10^5
 - 1\leq A_i,B_i\leq N
 - A_i \neq B_i

-----Input-----
Input is given from Standard Input in the following format:
N M
A_1 B_1
\vdots
A_M B_M

-----Output-----
Print the answer.

-----Sample Input-----
5 3
1 2
3 4
5 1

-----Sample Output-----
3

Dividing them into three groups such as \{1,3\}, \{2,4\}, and \{5\} achieves the goal.
user: You are given a tree with N vertices and N-1 edges. The vertices are numbered 1 to N, and the i-th edge connects Vertex a_i and b_i.
You have coloring materials of K colors.
For each vertex in the tree, you will choose one of the K colors to paint it, so that the following condition is satisfied:
 - If the distance between two different vertices x and y is less than or equal to two, x and y have different colors.
How many ways are there to paint the tree? Find the count modulo 1\ 000\ 000\ 007.
What is tree?
A tree is a kind of graph. For detail, please see: Wikipedia "Tree (graph theory)"

What is distance?
The distance between two vertices x and y is the minimum number of edges one has to traverse to get from x to y.

-----Constraints-----
 - 1 \leq N,K \leq 10^5
 - 1 \leq a_i,b_i \leq N
 - The given graph is a tree.

-----Input-----
Input is given from Standard Input in the following format:
N K
a_1 b_1
a_2 b_2
.
.
.
a_{N-1} b_{N-1}

-----Output-----
Print the number of ways to paint the tree, modulo 1\ 000\ 000\ 007.

-----Sample Input-----
4 3
1 2
2 3
3 4

-----Sample Output-----
6


There are six ways to paint the tree.
user: There are K items placed on a grid of squares with R rows and C columns. Let (i, j) denote the square at the i-th row (1 \leq i \leq R) and the j-th column (1 \leq j \leq C). The i-th item is at (r_i, c_i) and has the value v_i.
Takahashi will begin at (1, 1), the start, and get to (R, C), the goal. When he is at (i, j), he can move to (i + 1, j) or (i, j + 1) (but cannot move to a non-existent square).
He can pick up items on the squares he visits, including the start and the goal, but at most three for each row. It is allowed to ignore the item on a square he visits.
Find the maximum possible sum of the values of items he picks up.

-----Constraints-----
 - 1 \leq R, C \leq 3000
 - 1 \leq K \leq \min(2 \times 10^5, R \times C)
 - 1 \leq r_i \leq R
 - 1 \leq c_i \leq C
 - (r_i, c_i) \neq (r_j, c_j) (i \neq j)
 - 1 \leq v_i \leq 10^9
 - All values in input are integers.

-----Input-----
Input is given from Standard Input in the following format:
R C K
r_1 c_1 v_1
r_2 c_2 v_2
:
r_K c_K v_K

-----Output-----
Print the maximum possible sum of the values of items Takahashi picks up.

-----Sample Input-----
2 2 3
1 1 3
2 1 4
1 2 5

-----Sample Output-----
8

He has two ways to get to the goal:
 - Visit (1, 1), (1, 2), and (2, 2), in this order. In this case, the total value of the items he can pick up is 3 + 5 = 8.
 - Visit (1, 1), (2, 1), and (2, 2), in this order. In this case, the total value of the items he can pick up is 3 + 4 = 7.
Thus, the maximum possible sum of the values of items he picks up is 8.
user: Snuke, who loves animals, built a zoo.
There are N animals in this zoo. They are conveniently numbered 1 through N, and arranged in a circle.
The animal numbered i (2≤i≤N-1) is adjacent to the animals numbered i-1 and i+1. Also, the animal numbered 1 is adjacent to the animals numbered 2 and N, and the animal numbered N is adjacent to the animals numbered N-1 and 1.
There are two kinds of animals in this zoo: honest sheep that only speak the truth, and lying wolves that only tell lies.
Snuke cannot tell the difference between these two species, and asked each animal the following question: "Are your neighbors of the same species?" The animal numbered i answered s_i. Here, if s_i is o, the animal said that the two neighboring animals are of the same species, and if s_i is x, the animal said that the two neighboring animals are of different species.
More formally, a sheep answered o if the two neighboring animals are both sheep or both wolves, and answered x otherwise.
Similarly, a wolf answered x if the two neighboring animals are both sheep or both wolves, and answered o otherwise.
Snuke is wondering whether there is a valid assignment of species to the animals that is consistent with these responses. If there is such an assignment, show one such assignment. Otherwise, print -1.

-----Constraints-----
 - 3 ≤ N ≤ 10^{5}
 - s is a string of length N consisting of o and x.

-----Input-----
The input is given from Standard Input in the following format:
N
s

-----Output-----
If there does not exist an valid assignment that is consistent with s, print -1.
Otherwise, print an string t in the following format. The output is considered correct if the assignment described by t is consistent with s.
 - t is a string of length N consisting of S and W.
 - If t_i is S, it indicates that the animal numbered i is a sheep. If t_i is W, it indicates that the animal numbered i is a wolf.

-----Sample Input-----
6
ooxoox

-----Sample Output-----
SSSWWS

For example, if the animals numbered 1, 2, 3, 4, 5 and 6 are respectively a sheep, sheep, sheep, wolf, wolf, and sheep, it is consistent with their responses. Besides, there is another valid assignment of species: a wolf, sheep, wolf, sheep, wolf and wolf.
Let us remind you: if the neiboring animals are of the same species, a sheep answers o and a wolf answers x. If the neiboring animals are of different species, a sheep answers x and a wolf answers o.
user: You have a sequence A composed of N positive integers: A_{1}, A_{2}, \cdots, A_{N}.
You will now successively do the following Q operations:
 - In the i-th operation, you replace every element whose value is B_{i} with C_{i}.
For each i (1 \leq i \leq Q), find S_{i}: the sum of all elements in A just after the i-th operation.

-----Constraints-----
 - All values in input are integers.
 -  1 \leq N, Q, A_{i}, B_{i}, C_{i} \leq 10^{5} 
 -  B_{i} \neq C_{i} 

-----Input-----
Input is given from Standard Input in the following format:
N
A_{1} A_{2} \cdots A_{N}
Q
B_{1} C_{1}
B_{2} C_{2}
\vdots
B_{Q} C_{Q}

-----Output-----
Print Q integers S_{i} to Standard Output in the following format:
S_{1}
S_{2}
\vdots
S_{Q}

Note that S_{i} may not fit into a 32-bit integer.

-----Sample Input-----
4
1 2 3 4
3
1 2
3 4
2 4

-----Sample Output-----
11
12
16

Initially, the sequence A is 1,2,3,4.
After each operation, it becomes the following:
 - 2, 2, 3, 4
 - 2, 2, 4, 4
 - 4, 4, 4, 4
user: We say that a odd number N is similar to 2017 when both N and (N+1)/2 are prime.
You are given Q queries.
In the i-th query, given two odd numbers l_i and r_i, find the number of odd numbers x similar to 2017 such that l_i ≤ x ≤ r_i.

-----Constraints-----
 - 1≤Q≤10^5
 - 1≤l_i≤r_i≤10^5
 - l_i and r_i are odd.
 - All input values are integers.

-----Input-----
Input is given from Standard Input in the following format:
Q
l_1 r_1
:
l_Q r_Q

-----Output-----
Print Q lines. The i-th line (1≤i≤Q) should contain the response to the i-th query.

-----Sample Input-----
1
3 7

-----Sample Output-----
2

 - 3 is similar to 2017, since both 3 and (3+1)/2=2 are prime.
 - 5 is similar to 2017, since both 5 and (5+1)/2=3 are prime.
 - 7 is not similar to 2017, since (7+1)/2=4 is not prime, although 7 is prime.
Thus, the response to the first query should be 2.
user: Takahashi has a string S of length N consisting of digits from 0 through 9.
He loves the prime number P. He wants to know how many non-empty (contiguous) substrings of S - there are N \times (N + 1) / 2 of them - are divisible by P when regarded as integers written in base ten.
Here substrings starting with a 0 also count, and substrings originated from different positions in S are distinguished, even if they are equal as strings or integers.
Compute this count to help Takahashi.

-----Constraints-----
 - 1 \leq N \leq 2 \times 10^5
 - S consists of digits.
 - |S| = N
 - 2 \leq P \leq 10000
 - P is a prime number.

-----Input-----
Input is given from Standard Input in the following format:
N P
S

-----Output-----
Print the number of non-empty (contiguous) substrings of S that are divisible by P when regarded as an integer written in base ten.

-----Sample Input-----
4 3
3543

-----Sample Output-----
6

Here S = 3543. There are ten non-empty (contiguous) substrings of S:
 - 3: divisible by 3.
 - 35: not divisible by 3.
 - 354: divisible by 3.
 - 3543: divisible by 3.
 - 5: not divisible by 3.
 - 54: divisible by 3.
 - 543: divisible by 3.
 - 4: not divisible by 3.
 - 43: not divisible by 3.
 - 3: divisible by 3.
Six of these are divisible by 3, so print 6.
user: There are N towns in the State of Atcoder, connected by M bidirectional roads.
The i-th road connects Town A_i and B_i and has a length of C_i.
Joisino is visiting R towns in the state, r_1,r_2,..,r_R (not necessarily in this order).
She will fly to the first town she visits, and fly back from the last town she visits, but for the rest of the trip she will have to travel by road.
If she visits the towns in the order that minimizes the distance traveled by road, what will that distance be?

-----Constraints-----
 - 2≤N≤200
 - 1≤M≤N×(N-1)/2
 - 2≤R≤min(8,N) (min(8,N) is the smaller of 8 and N.)
 - r_i≠r_j (i≠j)
 - 1≤A_i,B_i≤N, A_i≠B_i
 - (A_i,B_i)≠(A_j,B_j),(A_i,B_i)≠(B_j,A_j) (i≠j)
 - 1≤C_i≤100000
 - Every town can be reached from every town by road.
 - All input values are integers.

-----Input-----
Input is given from Standard Input in the following format:
N M R
r_1 ... r_R
A_1 B_1 C_1
:
A_M B_M C_M

-----Output-----
Print the distance traveled by road if Joisino visits the towns in the order that minimizes it.

-----Sample Input-----
3 3 3
1 2 3
1 2 1
2 3 1
3 1 4

-----Sample Output-----
2

For example, if she visits the towns in the order of 1, 2, 3, the distance traveled will be 2, which is the minimum possible.