P9129 [USACO23FEB] Piling Papers G

Farmer John wrote down $N (1 \le N \le 300)$ digits on pieces of paper. For each $i \in [1,N]$, the ith piece of paper contains digit $a_i (1 \le a_i \le 9)$. The cows have two favorite integers $A$ and $B(1 \le A \le B

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### Explanation for Sample 1 For the first query, there are nine ways Bessie can stack papers when reading the interval $[1,2]$: - Bessie can ignore $1$ then ignore $2$, getting $0$. - Bessie can ignore $1$ then add $2$ to the top of the stack, getting $2$. - Bessie can ignore $1$ then add $2$ to the bottom of the stack, getting $2$. - Bessie can add $1$ to the top of the stack then ignore $2$, getting $1$. - Bessie can add $1$ to the top of the stack then add $2$ to the top of the stack, getting $21$. - Bessie can add $1$ to the top of the stack then add $2$ to the bottom of the stack, getting $12$. - Bessie can add $1$ to the bottom of the stack then ignore $2$, getting $1$. - Bessie can add $1$ to the bottom of the stack then add $2$ to the top of the stack, getting $21$. - Bessie can add $1$ to the bottom of the stack then add $2$ to the bottom of the stack, getting $12$. Only the $2$ ways that give $21$ yield a number between $13$ and $327$, so the answer is $2$. ### SCORING - Inputs $2-3$: $B