Suppose $2a-3b = -23$. Given that $a$ and $b$ are consecutive integers, and $a<b$, what is the value of $a$?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Suppose $2a-3b = -23$. Given that $a$ and $b$ are consecutive integers, and $a<b$, what is the value of $a$?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
20
Suppose $2a-3b = -23$. Given that $a$ and $b$ are consecutive integers, and $a<b$, what is the value of $a$?
train