n, q = map(int, input().split())
s = input()

for i in range(q):
    l, r, k = map(int, input().split())
    x = s[l-1:r]
    count = 1
    for j in range(1, len(x)):
        if x[j] != x[j-1]:
            count += 1
    # count は文字列 x の長さの最小値

    # 0 を 1 に置き換える場合
    if x[0] == '0':
        for j in range(1, len(x)):
            if k == 0:
                break
            if x[j] == '1':
                count -= 1
                k -= 1
    # 1 を 0 に置き換える場合
    else:
        for j in range(1, len(x)):
            if k == 0:
                break
            if x[j] == '0':
                count -= 1
                k -= 1
    
    print(count)