N, Q = map(int,input().split())
S = input()
lrx = [list(map(int,input().split( ))) for _ in range(Q)]

cs = {
    "a":1,"b":2,"c":3,"d":4,"e":5,
    "f":6,"g":7,"h":8,"i":9,"j":10,
    "k":11,"l":12,"m":13,"n":14,"o":15,
    "p":16,"q":17,"r":18,"s":19,"t":20,
    "u":21,"v":22,"w":23,"x":24,"y":25,
    "z":26}
for i in cs:
    cs[i] = 0
al = "abcdefghijklmnopqrstuvwxyz"
sum = [{} for _ in range(N+1)]
for i in range(N+1):
    for j in cs:
        sum[i][j] = 0
    if i == 0:
        continue
    for j in cs:
        sum[i][j] = sum[i-1][j]
    sum[i][S[i-1]] += 1

for i in range(Q):
    l,r,x = lrx[i]
    for j in cs:
        cs[j] = sum[r][j] - sum[l-1][j]
    now = 0
    for j in range(len(al)):
        now += cs[al[j]]
        if now >= x:
            print(al[j])
            break