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UPEEC

Climbing Stairs

Easy#dynamic-programming· solved by 0 · time limit 2.0 s

You climb a staircase of nn steps, taking 1 or 2 steps at a time. In how many distinct ways can you reach the top? Print the answer modulo 109+710^9+7.

Input

A single integer nn.

Output

The number of ways modulo 1000000007.

Constraints

1≤n≤1061 \le n \le 10^6

Sample 1

Input

2

Output

2

Sample 2

Input

3

Output

3

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