You have $n$ coins with positive integer values. The coins are numbered $1,2,\dots,n$ .
Your task is to process $q$ queries of the form: "if you can use coins $a \dots b$ , what is the smallest sum you cannot produce?"
The first input line has two integers $n$ and $q$ : the number of coins and queries.
The second line has $n$ integers $x_1,x_2,\dots,x_n$ : the value of each coin.
Finally, there are $q$ lines that describe the queries. Each line has two values $a$ and $b$ : you can use coins $a \dots b$ .
Print the answer for each query.
5 3 2 9 1 2 7 2 4 4 4 1 5· \n · · · · \n · \n · \n · \n
4 1 6\n \n \n
First you can use coins $[9,1,2]$ , then coins $[2]$ and finally coins $[2,9,1,2,7]$ .