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Description

Crahc gives you a string $S$ consisting $\texttt{a},\texttt{b}$ and $\texttt{c}$. Denote the length of $S$ as $n\,(1\leq n\leq 10^4)$.

You need to convert $S$ into the decimal representation of $n$. For example, convert the string $\texttt{abbac}$ into $\texttt{5}$.

Each conversion step involves two strings $X,Y\,(|X|,|Y|\leq 10^4)$, where $X$ is not a substring of $Y$ (also, $X$ is not empty). Note that both $X$ and $Y$ can only consist of lowercase letters or digits. The single conversion step is defined as follows:

1. Find the first occurrence of $X$ in $S$.
2. Replace the first occurrence of $X$ with $Y$.
3. Repeat the above steps until no more occurrences of $X$ can be found in $S$.

Crahc is impatient, so you can only perform up to $20$ steps. At any time (including when performing one step), the length of $S$ should not exceed $10^4$.

Note that this problem does not require any input. You are only required to provide the steps for your conversion. Your solution must work for all valid strings.

Format

The first line contains a single integer $k\,(1\leq k\leq 20)$, the number of conversion steps you will perform.

The next $k$ lines, each line contains two strings $X,Y$, separated by a comma, representing the conversion step from $X$ to $Y$.

Samples

The example is for illustration of the format only; it may be incorrect.

3
bb,
ac,2x
a2x,5

It works for $S=\texttt{abbac}$.