Harryxun/stf_run huggingface dataset:
n, q = map(int, input().split())
s = input()

query = [list(input().split()) for _ in range(q)]

# 左に落ちる (1から, leftで判断(leftは落ちる個数))
left = 0
right = n+1
while right - left > 1:
    mid = (left + right) // 2
    index = mid - 1
    for w, dir in query:
        if s[index] != w:
            continue
        if dir == 'R':
            index += 1
        elif dir == 'L':
            index -= 1

        if index == n:
            right = mid
            break
        elif index == -1:
            left = mid
            break
    if index != -1:
        right = mid
c1 = left

# 右 (leftで判断(leftが落ちないギリギリ。最大はn-1, 最小は-1))
left = -1
right = n+1
while right - left > 1:
    mid = (left + right) // 2
    index = mid
    for w, dir in query:
        if s[index] != w:
            continue
        if dir == 'R':
            index += 1
        elif dir == 'L':
            index -= 1

        if index == n:
            right = mid
            break
        elif index == -1:
            left = mid
            break
    if index != n:
        left = mid

c2 = n - 1 - left

print(n - c1 - c2)


### FIXED CODE ###

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

query = [list(input().split()) for _ in range(q)]

# 左に落ちる。leftから左(leftを含む)は左に落ちて、rightから右は左に落ちない。
left = -1
right = n
while right - left > 1:
    mid = (left + right) // 2
    index = mid
    for w, dir in query:
        if s[index] != w:
            continue
        if dir == 'R':
            index += 1
        elif dir == 'L':
            index -= 1

        if index == n:
            right = mid
            break
        elif index == -1:
            left = mid
            break
    if index != -1:
        right = mid
c1 = left + 1

# 右に落ちる。leftから左(leftを含む)は右に落ちず、rightから右は右に落ちる。
left = -1
right = n
while right - left > 1:
    mid = (left + right) // 2
    index = mid
    for w, dir in query:
        if s[index] != w:
            continue
        if dir == 'R':
            index += 1
        elif dir == 'L':
            index -= 1

        if index == n:
            right = mid
            break
        elif index == -1:
            left = mid
            break
    if index != n:
        left = mid

c2 = n - 1 - left

print(n - c1 - c2)
N = int(input())
A = list(map(int,input().split()))
C = [a//400 for a in A if s<3200]
m = len(set(C))
print(max(1,m),m+N-len(C))

### FIXED CODE ###

N = int(input())
A = list(map(int,input().split()))
C = [a//400 for a in A if a<3200]
m = len(set(C))
print(max(1,m),m+N-len(C))
cards = {
        'S': [0 for _ in range(13)],
        'H': [0 for _ in range(13)],
        'C': [0 for _ in range(13)],
        'D': [0 for _ in range(13)],
}

n = int(input())
for _ in range(n):
    (s, r) = input().split()
    cards[s][int(r) - 1] = 1
print(data)

for s in ('S', 'H', 'C', 'D'):
    for r in range(13):
        if cards[s][r] == 0:
            print('{0:s} {1:d}.format(s, r+1))

### FIXED CODE ###

cards = {
        'S': [0 for _ in range(13)],
        'H': [0 for _ in range(13)],
        'C': [0 for _ in range(13)],
        'D': [0 for _ in range(13)],
        }
  
n = int(input())
for _ in range(n):
    (s, r) = input().split()
    r = int(r)
    cards[s][r - 1] = r
  
for s in ('S', 'H', 'C', 'D'):
    for r in range(13):
        if cards[s][r] == 0:
            print( '{0:s} {1:d}'.format(s, r+1))
x,y=map(int,input().split())
if x<y:
  print("<")
elif x>y:
  print(">")
else:
  print("=")

### FIXED CODE ###

x,y=map(str,input().split())
if x<y:
  print("<")
elif x>y:
  print(">")
else:
  print("=")
import sys
n = sys.stdin.readline()
m=n*n*n
print(m)

### FIXED CODE ###

n=input()
num=int(n)
print(num*num*num)
# D - Even Relation

import sys
sys.setrecursionlimit = 10**9

n = int(input())

# adjacency list
alist = [[] for _ in range(n)]

for _ in range(n-1):
    u, v, w = map(int, input().split())
    u -= 1
    v -= 1
    alist[u].append((v, w))
    alist[v].append((u, w))

#print(alist)

dlist = [-1] * n

def dfs(node, par, dist):
    dlist[node] = dist%2
    for i, j in alist[node]:
        if i==par:
            continue
        else:
            dfs(i, node, dist+j)

dfs(0,0,0)

for i in range(n):
    print(dlist[i])    


### FIXED CODE ###

# D - Even Relation

from collections import deque

n = int(input())

# adjacency list
alist = [[] for _ in range(n)]

for _ in range(n-1):
    u, v, w = map(int, input().split())
    u -= 1
    v -= 1
    alist[u].append((v, w%2))
    alist[v].append((u, w%2))

#print(alist)

dlist = [-1] * n
dlist[0] = 0

q = deque()
q.append(0)

while len(q)>0:
    node = q.popleft()
    for i, j in alist[node]:
        if dlist[i]<0:
            q.append(i)
            dlist[i] = (dlist[node] + j)%2
        else:
            continue

'''
def dfs(node, par, dist):
    dlist[node] = dist%2
    for i, j in alist[node]:
        if i==par:
            continue
        else:
            dfs(i, node, dist+j)
dfs(0,0,0)
'''

for i in range(n):
    print(dlist[i])
N = int(input())
A = [0 for i in range(N)]
for i in range(N):
    A[i] = map(str,input().split())
for i in range(N):
    A[i].append(str(i))

B = sorted(A, key=lambda x: x[1], reverse=True)

C = sorted(B, key=lambda x: x[0])

for i in range(N):
    print(int(C[i][2])+1)

### FIXED CODE ###


N = int(input())
A = [0 for i in range(N)]
for i in range(N):
    A[i] = list(map(str,input().split()))
for i in range(N):
    A[i].append(str(i+1))
for i in range(N):
    A[i][1] = int(A[i][1]) 


B = sorted(A, key=lambda x: x[1], reverse=True)

C = sorted(B, key=lambda x: x[0])

for i in range(N):
    print(int(C[i][2]))
# coding: utf-8
# Your code here!
line= list(map(int,input().split()))
N = line[0]
K = line[1]
#0~Nの連続した整数から
#K個以上(N+1)個以下だけ選ぶ
answer = 0
for i in range (K,N+2):
    minit = i*(i-1)/2
    maximum = (2*N-i+1)*i/2
    
    num = maximum-minit+1
    answer += num
 
if answer >=(10**9+7):
    print(int(answer%(10**9+7)))
    
else:
    print(int(answer))

### FIXED CODE ###

# coding: utf-8
# Your code here!
r = int(input())
pai = 3.14159265359
rounds = 2*r*pai
print(rounds)
x=input()
print(x**3)



### FIXED CODE ###

x=input()
y=int(x)
y=y**3
print(y)
N,K = map(int, input().split())
S = input()
print(*[s if i != K else s.lower() for i in range(N)])


### FIXED CODE ###

N,K = map(int, input().split())
S = input()
print(''.join([S[i]if i+1 != K else S[i].lower() for i in range(N)]))
N, M = map(int, input().split())
H = list(map(int, input().split()))
A = [0] * N
B = [0] * N
for i in range(M):
    A[i], B[i] = map(int, input().split())

ans = 0
for i in range(N):
    count = 0
    good = 0
    for j in range(M):
        if A[j] == i + 1:
            count += 1
            if H[B[j] - 1] < H[i]:
                good += 1
        if B[j] == i + 1:
            count += 1
            if H[A[j] - 1] < H[i]:
                good += 1
    if count == good:
        ans += 1

print(ans)


### FIXED CODE ###

#!/usr/bin/env python3
import sys
def input():
    return sys.stdin.readline()[:-1]

def main():
    N, M = map(int, input().split())
    H = list(map(int, input().split()))
    A = [0] * M
    B = [0] * M
    for i in range(M):
        A[i], B[i] = map(int, input().split())

    l = [1] * N
    for i in range(M):
        if H[A[i] - 1] < H[B[i] - 1]:
            l[A[i] - 1] -= 1
        elif H[A[i] - 1] > H[B[i] - 1]:
            l[B[i] - 1] -= 1
        else:
            l[A[i] - 1] -= 1
            l[B[i] - 1] -= 1
    print(l.count(1))

if __name__ == '__main__':
    main()
import math
N = int(input())
h = list(map(int, input().split(' ')))
h.append(math.inf)
h.append(math.inf)
dp = [math.inf for _ in range(N + 100)]
dp[0] = 0
for i in range(N-1):
  dp[i+1] = min(dp[i] + abs(h[i+1] - h[i]), dp[i+1])
  dp[i+2] = min(dp[i] + abs(h[i+2] - h[i]), dp[i+2])
print(dp[N-1])

### FIXED CODE ###

f_inf = float('inf')
N = int(input())
h = list(map(int, input().split(' ')))
h.append(f_inf)
h.append(f_inf)
dp = [f_inf for _ in range(N + 100)]
dp[0] = 0
for i in range(N-1):
  dp[i+1] = min(dp[i] + abs(h[i+1] - h[i]), dp[i+1])
  dp[i+2] = min(dp[i] + abs(h[i+2] - h[i]), dp[i+2])
print(dp[N-1])
import sys
import numpy as np
input = sys.stdin.readline

def main():
    N, M = map(int, input().split())
    abc = []
    for i in range(M):
        a, b = map(int, input().split())
        c = np.array(list(map(int, input().split()))) - 1
        abc.append((a, b, c))
    abc = sorted(abc)
    INF = int(1e10)
    dp = np.full(N, INF, dtype=int)

    ans = 0
    for i in range(M):
        a, b, c = abc[i]
        now = sum(dp[c])
        if a < now:
            dp[c] = np.minimum(dp[c], a)
            ans += a

    ok = True
    for i in range(N):
        if dp[i] == INF:
            ok = False
            break
    
    if ok:
        print(ans)
    else:
        print(-1)


if __name__ == "__main__":
    main()

### FIXED CODE ###

import sys
import numpy as np
input = sys.stdin.readline

def main():
    N, M = map(int, input().split())
    INF = int(1e10)
    dp = [INF] * (1 << N)
    dp[0] = 0
    bits = set()
    bits.add(0)
    for i in range(M):
        a, b = map(int, input().split())
        c = list(map(int, input().split()))
        key = 0
        for t in c:
            key += 1 << (t - 1)
        add_bits = set()
        for bit in bits:
            tmp = bit | key
            if dp[bit] + a < dp[tmp]:
                dp[tmp] = dp[bit] + a
                add_bits.add(tmp)
        bits |= add_bits
    
    if dp[(1 << N) - 1] == INF:
        print(-1)
    else:
        print(dp[(1 << N) - 1])

if __name__ == "__main__":
    main()
n,k=map(int,input().split())
ans=0
if k%2==1:
    ans=(n//k)**3
    print(ans)
else:
    print((n//k)**3+(n+(k//2)//k)**3)



### FIXED CODE ###

n=int(input())
a=list(map(int,input().split()))
print(sum(a)-n)
import bisect
import operator
from collections import Counter, deque
from fractions import gcd
from functools import lru_cache
from functools import reduce
import functools
import heapq
import itertools
import math
import numpy as np
import re
import sys

sys.setrecursionlimit(10000)
INF = float('inf')

N, M = list(map(int, input().split()))
A = list(map(int, input().split()))
B, C = zip(*[list(map(int, input().split())) for _ in range(M)])

heap = A
heapq.heapify(heap)


for b, c in zip(B, C):
    for _ in range(b):
        a = heapq.heappop(heap)
        if a < c:
            heapq.heappush(heap, c)
        else:
            heapq.heappush(heap, a)
            break

print(sum(heap))


### FIXED CODE ###

import sys

sys.setrecursionlimit(10000)
INF = float('inf')

N, M = list(map(int, input().split()))
A = list(map(int, input().split()))
CB = [list(map(int, reversed(input().split()))) for _ in range(M)]

A.sort()
CB.sort()

ans = 0
for _ in range(N):
    a = A[-1] if A else -INF
    c, b = CB[-1] if CB else (-INF, -INF)
    if a > c:
        ans += a
        A.pop()
    else:
        ans += c
        CB[-1][1] -= 1
        if CB[-1][1] <= 0:
            CB.pop()
print(ans)
A, B = int(input().split())

s = A + B
d = A - B
m = A * B

print(max(s, d, m))

### FIXED CODE ###

A, B = map(int, input().split())

s = A + B
d = A - B
m = A * B

print(max(s, d, m))
a=int(input())
b=[]
if a==0:
  print(0)
else:
  while a:
	b.append(a&1)
	a=int((a-(a&1))/(-2))
  print(''.join(map(str,b)))

### FIXED CODE ###

a=int(input())
b=[]
if a==0:
	print(0)
while a:
	b.append(a&1)
	a-=a&1
	a=int(a/-2)

print(''.join(map(str,b[::-1])))
from operator import itemgetter

n, k = map(int, input().split())
td = [tuple(int(x) for x in input().split()) for _ in range(n)]

a = sorted(td, key=itemgetter(1), reverse=True)

ans = [0]
s = set()
t = []
for i in range(k):
    ans[0] += a[i][1]
    if a[i][0] not in s:
        s.add(a[i][0])
    else:
        t.append(a[i][1])

p = len(s)
q = len(t) - 1

if q < 0:
    print(ans[0] + k * k)
    exit()

v = []
for i in range(k, n):
    if a[i][0] not in s:
        s.add(a[i][0])
        v.append(a[i][1])

ans[0] += p * p
d = 0

for x in v:
    ans.append(ans[d] + x - t[q] + (p + 1) * (p + 1) - p * p)
    p += 1
    d += 1
    q -= 1
    if q < 0:
        break

print(max(ans))

### FIXED CODE ###

a = list(map(int, input().split()))

a = sorted(a)

print(a[0] * a[1] // 2)
x,y = map(int,input())
if x%y == 0:
  print(-1)
else:
  print(x)

### FIXED CODE ###

x,y = map(int,input().split())
if x%y == 0:
  print(-1)
else:
  print(x)
N = int(input())
List = list(map(int, input().split()))
Lists = []
count = 0
idou = 0
while idou < N-1:
  while List[idou] >= List[idou+1]:
    idou = idou+1
    count = count+1
  Lists.addent(count)
  count = 0
print(max(count))

### FIXED CODE ###

def resolve():
    N = int(input())
    H = list(map(int, input().split()))
    ans = [0]
    count = 0
    for i in range(len(H) - 1):
        if H[i] >= H[i + 1]:
            count += 1
        else:
            ans.append(count)
            count = 0
    if count != 0:
        ans.append(count)
    print(max(ans))
resolve()
N, K = map(int, input().split())
A = list(map(int, input().split()))

TMP = [0] * N

for i in A:
    TMP[i-1] += 1

filter_TMP = sorted([i for i in TMP if i > 0])

n = sum( x > 0 for x in filter_TMP)

cnt = 0
ans = 0
while n > K:
    ans += filter_TMP[cnt]
    del filter_TMP[cnt]
    cnt += 1
    n -= 1

print(ans)

### FIXED CODE ###

N, K = map(int, input().split())
A = list(map(int, input().split()))

TMP = [0] * N

for i in A:
    TMP[i-1] += 1

filter_TMP = sorted([i for i in TMP if i > 0], reverse=True)

max_ball = 0
cnt = 1
for i in filter_TMP:
    if cnt <= K:
        max_ball += i
        cnt += 1
    else:
        break
    

print(N - max_ball)
def solve(s,p):
    if s[0]!='[':
        return[p//1000,p//100%10,p//10%10,p%10][ord(s[0])-ord('a')]
    i=3
    while s.count('[',2,i)!=s.count(']',2,i):
        i+=1
    j=i+1
    while s.count('[',i,j)!=s.count(']',i,j):
        j+=1
    l=solve(s[2:i],p)
    r=solve(s[i:j],p)
    if s[1]=='+':
        return l|r
    elif s[1]=='*':
        return l&r
    else:
        return l^r
while True:
    s=input()
    if s=='.':break
    p=int(input())
    a=solve(s,p)
    c=0
    for i in range(10000):
        if solve(s,i)==a:
            c+=1
    print(a,c)


### FIXED CODE ###

def solve(s,p):
    if s[0]!='[':
        return[p//1000,p//100%10,p//10%10,p%10][ord(s[0])-ord('a')]
    i=3
    cs=s[2]=='['
    ce=0
    while cs!=ce:
        if s[i]=='[':
            cs+=1
        elif s[i]==']':
            ce+=1
        i+=1
    j=i+1
    cs=s[i]=='['
    ce=0
    while cs!=ce:
        if s[j]=='[':
            cs+=1
        elif s[j]==']':
            ce+=1
        j+=1
    l=solve(s[2:i],p)
    r=solve(s[i:j],p)
    if s[1]=='+':
        return l|r
    elif s[1]=='*':
        return l&r
    else:
        return l^r
while True:
    s=input()
    if s=='.':break
    p=int(input())
    a=solve(s,p)
    c=0
    for i in range(10000):
        if solve(s,i)==a:
            c+=1
    print(a,c)
input = input().split()

cntYes = 0
for C in range(1,4):
    ans = int(input[0])*int(input[1])*C
    if ans%2!=0:
       cntYes += 1
if cnt>0:
    print('Yes')
else:
    print('No')

### FIXED CODE ###

input = input().split()

cntYes = 0
for C in range(1,4):
    ans = int(input[0])*int(input[1])*C
    if ans%2!=0:
       cntYes += 1
if cntYes>0:
    print('Yes')
else:
    print('No')
#! /usr/bin/env python3

import sys
int1 = lambda x: int(x) - 1
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(500000)
MOD = pow(10, 9) + 7

N, K, *A = map(int, read().split())

if K == N:
    ans = 1
    for a in A:
        ans = ans * a % MOD
    print(ans)
    sys.exit()

A_pos = [a for a in A if a >= 0]
A_neg = [a for a in A if a < 0]

if len(A_pos) == 0:
    if K % 2 == 1:
        A_neg.sort(reverse=True)
    else:
        A_neg.sort()
    ans = 1
    for a in A_neg[:K]:
        ans = ans * a % MOD
    print(ans)
    sys.exit()

A_pos.sort(reverse=True)
A_neg.sort()
ans = 1
r = K
if r % 2 == 1:
    ans = ans * A_pos[0] % MOD
    A_pos = A_pos[1:]
    r -= 1

while r > 0:
    if len(A_pos) <= 1:
        ans = ans * A_neg[0] * A_neg[1] % MOD
    elif len(A_neg) <= 1:
        ans = ans * A_pos[0] * A_pos[1] % MOD

    else:
        acc_pos = A_pos[0] * A_pos[1]
        acc_neg = A_neg[0] * A_neg[1]

    if acc_pos > acc_neg:
        ans = ans * acc_pos % MOD
    else:
        ans = ans * acc_neg % MOD
    r -= 2
print(ans % MOD)


### FIXED CODE ###

#! /usr/bin/env python3

import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(500000)
MOD = pow(10, 9) + 7

N, K, *A = map(int, read().split())

if K == N:
    ans = 1
    for a in A:
        ans = ans * a % MOD
    print(ans)
    sys.exit()

A_pos = [a for a in A if a >= 0]
A_neg = [a for a in A if a < 0]

if len(A_pos) == 0:
    if K % 2 == 1:
        A_neg.sort(reverse=True)
    else:
        A_neg.sort()
    ans = 1
    for a in A_neg[:K]:
        ans = ans * a % MOD
    print(ans)
    sys.exit()

A_pos.sort()
A_neg.sort(reverse=True)
ans = 1
r = K
if r % 2 == 1:
    ans = ans * A_pos.pop() % MOD
    r -= 1

while r > 0:
    if len(A_pos) <= 1:
        ans = ans * A_neg.pop() * A_neg.pop() % MOD
    elif len(A_neg) <= 1:
        ans = ans * A_pos.pop() * A_pos.pop() % MOD

    else:
        acc_pos = A_pos[-1] * A_pos[-2]
        acc_neg = A_neg[-1] * A_neg[-2]

        if acc_pos > acc_neg:
            ans = ans * A_pos.pop() * A_pos.pop() % MOD
        else:
            ans = ans * A_neg.pop() * A_neg.pop() % MOD
    r -= 2
print(ans % MOD)
N, M = map(int, input().split())

def find(x):
    if x == parents[x]:
        return x
    else:
        x = find(parents[x])
        return x
    
def same(x, y):
    if x==y:
        pass
    else:
        parents[x] = y

for _ in range(M):
    A, B = map(int, input().split())
    x, y = find(A), find(B)
    same(x, y)

print(len(set(uni.parents)) - 2)

### FIXED CODE ###

N, M = map(int, input().split())
parents = [i for i in range(N+1)]

def find(x):
    if x == parents[x]:
        return x
    else:
        parents[x] = find(parents[x])
        return parents[x]
    
def same(A, B):
    x, y = find(A), find(B)
    if x==y:
        return
    else:
        parents[x] = y

for _ in range(M):
    A, B = map(int, input().split())
    same(A, B)
    
for i in range(N):
    find(i+1)

print(len(set(parents)) - 2)
A = input()
B = input()
C = print(B[:len(B)])
if A == C:
  D = "Yes"
  else:
    D = "No"
print(D)

### FIXED CODE ###

A = input()
B = input()
C = B[:len(B)-1]
if A == C:
  D = "Yes"
else:
  D = "No"
print(D)
numlist = list(input().split())
print(sorted(numlist,key=lambda x:numlist.sount(x))[0])

### FIXED CODE ###

numlist = list(input().split())
print(sorted(numlist,key=lambda x:numlist.count(x))[0])
s = list(map(str,input().split()))
if s[0]=='Y' and s[1]=='A' and s[2]=='K' and s[3]=='I':
    print('Yes')
else:
    print('No')

### FIXED CODE ###

import sys
s = list(str(input()))
if len(s)<4:
    print('No')
    sys.exit()
if s[0]=='Y' and s[1]=='A' and s[2]=='K' and s[3]=='I':
    print('Yes')
else:
    print('No')
sum = 0

num = int(input())

if num < 1 or num > 10 :
    return
    
for i in range(num) :
    money, currency = input().split()
    money = double(money)
    if currency == 'JPY' :
        sum += money
    else :
        sum += money * 380000

print(sum)

### FIXED CODE ###

sum = 0

num = int(input())

for i in range(num) :
    money, currency = input().split()
    money = float(money)
    if currency == 'JPY' :
        sum += money
    else :
        sum += money * 380000

print(sum)
n = int(input())

ans = -1
for x in range(n):
    if int(x*1.08)==n:
        ans = x

if ans != -1:
    print(ans)
else:
    print(':(')

### FIXED CODE ###

m1, d1 = map(int, input().split())
m2, d2 = map(int, input().split())

if m1 != m2 and d2 == 1:
    print(1)
else:
    print(0)
n,m,r=map(int,input().split())
a,b=sorted([n-1,r-m*n])
A=1
for i in range(a):A*=i+1
B=A
for i in range(a,b):B*=i+1
C=B
for i in range(b,a+b):C*=i+1
print([int(C/B/A),0][a<1])


### FIXED CODE ###

n,m,r=map(int,input().split())
r-=m*n
if r<0:print(0)
else:
 d=1
 for i in range(r):d*=i+1
 u=1
 for i in range(r):u*=i+n
 print(u//d)
def main():
    import sys
    input = sys.stdin.readline
    s = input().strip()
    N = len(s)
    l = -1
    r = N
    while l < r:
        l += 1
        r -= 1
        while s[l] == 'x':
            l += 1
        while s[r] == 'x':
            r -= 1
        if s[l] != s[r]:
            print(-1)
            exit()
    
    ans = 0
    if l > r:
        l, r = r, l
        if r - l % 2 != 0:
            ans += 1
    
    while l != -1 or r != N:
        if l == -1:
            ans += N - r
            break
        if r == N:
            ans += l + 1
            break
        if s[l] == s[r]:
            l -= 1
            r += 1
            continue
        elif s[l] == 'x':
            ans += 1
            l -= 1
        elif s[r] == 'x':
            ans += 1
            r += 1
        
    print(ans)

if __name__ == '__main__':
    main()

### FIXED CODE ###

def main():
    import sys
    input = sys.stdin.readline
    s = input().strip()
    N = len(s)
    l = -1
    r = N
    if len(set(s)) == 1:
        print(0)
        exit()
    while l < r:
        l += 1
        r -= 1
        while s[l] == 'x':
            l += 1
        while s[r] == 'x':
            r -= 1
        if s[l] != s[r]:
            print(-1)
            exit()
    
    ans = 0
    while l != -1 or r != N:
        if l == -1:
            ans += N - r
            break
        if r == N:
            ans += l + 1
            break
        if s[l] == s[r]:
            l -= 1
            r += 1
            continue
        elif s[l] == 'x':
            ans += 1
            l -= 1
        elif s[r] == 'x':
            ans += 1
            r += 1
        
    print(ans)

if __name__ == '__main__':
    main()
N,A = map(int,input().split())

if N/500 >=1 and N%500 <= A:
  print("Yes")
else:
  print("No")

### FIXED CODE ###

N = int(input())
A = int(input())

if N%500 <= A:
  print("Yes")
else:
  print("No")
n = int(input())
r = [0] * (n - 1)
for i in range(n - 1):
  r[i] = i
print(sum(r) + (n - 1))

### FIXED CODE ###

n = int(input())
print(n * (n - 1) // 2)
color = input().split()
num = input().split()
choice = input()

for i in range(2):
  if choice == color[i]:
    num[i] = int(num[i]) - 1 
    
print(num)

### FIXED CODE ###

s = input()
c = ''
for i in range(len(s)):
  c += 'x'
  

print(c)