Find a sequence#8699

Find a sequence

1 second

128 megabytes

Very easy

A sequence of digits from $0$ to $9$ is given. The digits are provided one per line.

Your task is to read the numbers until three consecutive digits appear for the first time that form a strictly increasing sequence with step $1$ (for example: $2, 3, 4$ or $6, 7, 8$ ).

In other words, you need to detect three consecutive numbers $(a, b, c)$ (a, b, c) such that:

b = a + 1, c = b + 1

b = a + 1,\quad c = b + 1

As soon as such a triple appears, the input process stops.

Input

Each line contains one digit: $(0, 1, 2, \dots, 9)$ (0, 1, 2, \dots, 9).

Output

Print the number of digits read until the first occurrence of such a triple.

Examples

Example 1

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(a, b, c)

b = a + 1, c = b + 1

(0, 1, 2, \dots, 9)