Problem: You are given array a with n integers and m queries. The i-th query is given with three integers li, ri, xi.

For the i-th query find any position pi (li ≤ pi ≤ ri) so that api ≠ xi.

Input

The first line contains two integers n, m (1 ≤ n, m ≤ 2·105) — the number of elements in a and the number of queries.

The second line contains n integers ai (1 ≤ ai ≤ 106) — the elements of the array a.

Each of the next m lines contains three integers li, ri, xi (1 ≤ li ≤ ri ≤ n, 1 ≤ xi ≤ 106) — the parameters of the i-th query.

Output

Print m lines. On the i-th line print integer pi — the position of any number not equal to xi in segment [li, ri] or the value  - 1 if there is no such number.

Examples

Input

6 4
1 2 1 1 3 5
1 4 1
2 6 2
3 4 1
3 4 2


Output

2
6
-1
4

Solution (in PYTHON):

Solution:
# import sys
# sys.stdin = open("b.test.txt")

def main():
    n,m = map(int, raw_input().strip().split())
    p = [0] * 200005
    a = [0] * 200005
    _xs = map(int, raw_input().strip().split())
    for _i, x in enumerate(_xs):
        i = _i + 1
        a[i] = x
        p[i] = p[i - 1] if a[i] == a[i-1] else i - 1

    for i in xrange(m):
        l, r, x = [int(x) for x in raw_input().strip().split()]
        if(a[r] == x):
            if(p[r] >= l):
                print p[r]
            else:
                print -1

        else:
            print r

if __name__ == "__main__":
   main()