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 PYTHON3):

Solution:
n,m = [int(i) for i in input().split()]
a = input().split()
result = []
prev = [-1]*n

for i in range(1,n):
    if a[i] != a[i-1]:
        prev[i] = i-1
    else:
        prev[i] = prev[i-1]

for i in range(m):
    l,r,x = input().split()
    r = int(r)
    if a[r-1] != x:
        answer = r
    elif prev[r-1]<int(l)-1:
        answer = -1
    else:
        answer = prev[r-1]+1

    result.append(str(answer))

print('\n' .join(result))