Description

There is a program with several lines, and each line contains exactly one command. The possible commands are as follows:

• int a[N] Declare an array. The keyword is always int, never something else like long long. a denotes the name of an array (not necessarily a; it could be another letter or multiple letters, with length no more than $10$). After that is a pair of brackets containing either a number or a variable, indicating the array size (indices range from $0$ to $N-1$, $N\le100$). After the array is declared, all its elements are $0$.
• a[i] h Assign h to a[i] (i.e., a[i]=h). Here $h$ can be either a number or a variable, and $i$ can be either a number or a variable.
• cout h Output $h$, where $h$ must be a variable.

Input Format

Several lines: one command per line.

Output Format

For each output command (i.e., cout), print one line.

If an out-of-bounds array index is found on any line (note that only this type of error can occur; there will not be other issues such as redefinition), stop immediately regardless of how many commands remain below, ignore all remaining commands, and output -1.

int a[10]
a[a[0]] 2
cout a[0]

2

int a[10]
a[0] 10
cout a[0]
a[a[0]] 1
cout a[0]

10
-1

Hint

The number of lines does not exceed $10$. Variables may be nested, such as a[a[b[0]]], etc. Uppercase letters may also appear. All numbers that appear do not exceed $10^9$, are not negative, and are not decimals.

Translated by ChatGPT 5