String insertion P21174

Implement an efficient data structure to keep a dynamic array A[0..] of strings, with two operations:

• ‘I’ $s$ $i$: Increase the size of $A$ by one (like A.push_back("");). Move every string at a position $j$ such that $j \ge i$ one position to its right. Store the string $s$ at the $i$-th position, which now is empty.

• ‘C’ $j$: Print the $j$-th character (0 based) of the whole array, considering the concatenation of all its strings from left to right.

Input

Input consists of just one case. Assume that each $s$ has between 1 and 10 lowercase letters, each $i$ is between 0 and the current number of strings, and each $j$ is between 0 and the current number of characters minus one. The total number of operations is at most $3 \cdot 10^5$. An ‘E’ marks the end of the input.

Output

Print a line with the letter at the $j$-th position for each ‘C’ operation.