Problem Statement
A balancing network is an abstract device built up of $N$ wires, thought of as running from left to right, and $M$ balancers that connect pairs of wires. The wires are numbered from $1$ to $N$ from top to bottom, and the balancers are numbered from $1$ to $M$ from left to right. Balancer $i$ connects wires $x_i$ and $y_i$ ($x_i < y_i$).

Each balancer must be in one of two states: up or down.
Consider a token that starts moving to the right along some wire at a point to the left of all balancers. During the process, the token passes through each balancer exactly once. Whenever the token encounters balancer $i$, the following happens:
- If the token is moving along wire
$x_i$and balancer$i$is in the down state, the token moves down to wire$y_i$and continues moving to the right. - If the token is moving along wire
$y_i$and balancer$i$is in the up state, the token moves up to wire$x_i$and continues moving to the right. - Otherwise, the token doesn't change the wire it's moving along.
Let a state of the balancing network be a string of length $M$, describing the states of all balancers. The $i$-th character is ^ if balancer $i$ is in the up state, and v if balancer $i$ is in the down state.
A state of the balancing network is called uniforming if a wire $w$ exists such that, regardless of the starting wire, the token will always end up at wire $w$ and run to infinity along it. Any other state is called non-uniforming.
You are given an integer $T$ ($1 \le T \le 2$). Answer the following question:
- If
$T = 1$, find any uniforming state of the network or determine that it doesn't exist. - If
$T = 2$, find any non-uniforming state of the network or determine that it doesn't exist.
Note that if you answer just one kind of questions correctly, you can get partial score.
Constraints
$2 \leq N \leq 50000$$1 \leq M \leq 100000$$1 \leq T \leq 2$$1 \leq x_i < y_i \leq N$- All input values are integers.
Partial Score
$800$points will be awarded for passing the testset satisfying$T = 1$.$800$points will be awarded for passing the testset satisfying$T = 2$.
Input
Input is given from Standard Input in the following format:
N M T
x_1 y_1
x_2 y_2
:
x_M y_M
Output
Print any uniforming state of the given network if $T = 1$, or any non-uniforming state if $T = 2$. If the required state doesn't exist, output -1.
样例
4 5 1
1 3
2 4
1 2
3 4
2 3
^^^^^
4 5 2
1 3
2 4
1 2
3 4
2 3
v^^^^
3 1 1
1 2
-1
2 1 2
1 2
-1
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