ShaysXIA/CodeInsightBench huggingface dataset:
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 655 ms):
import io,os
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline




def main():
    n = int(input())
    arr = list(map(int,input().split()))
    for i in range(n):
        arr[i] -= 1


    curr = [i for i in range(n)]

    ans = []


    for i in range(n):
        index = -1
        for j in range(n):
            if curr[j]==arr[i]:  
                index = j   
                break

        for j in range(index,n-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))
        for j in range(n-2,i-1,-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))        



    print(len(ans))
    for ele in ans:
        print(*ele)



main()


Solution 2 (runtime: 671 ms):
import bisect
from collections import deque
D = ((0, 1), (1, 0), (0, -1), (-1, 0))

# T = int(input())
T = 1



def solve():
    n = int(input())
    a = list(map(int, input().split()))
    a = list(reversed(a))
    p = [i+1 for i in range(n-1, -1, -1)]
    res = []
    # print(p)
    for idx, i in enumerate(a):
        l = bisect.bisect_right(p, -i, idx, n, key=lambda x: -x) - 1
        # print(f"searched {i} in {p[idx:n]} and found {p[l]} @ {l}")
        for jdx in range(l+1, n):
            res.append((p[jdx-1], p[jdx]))
            p[jdx-1], p[jdx] = p[jdx], p[jdx-1]
            # print(p)
        for jdx in range(n-1, idx, -1):
            res.append((p[jdx-1], p[jdx]))
            p[jdx-1], p[jdx] = p[jdx], p[jdx-1]
            # print(p)
    print(len(res))
    for i in res:
        print(i[0], i[1])

while(T):
    T-=1
    solve()
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 655 ms):
import io,os
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline




def main():
    n = int(input())
    arr = list(map(int,input().split()))
    for i in range(n):
        arr[i] -= 1


    curr = [i for i in range(n)]

    ans = []


    for i in range(n):
        index = -1
        for j in range(n):
            if curr[j]==arr[i]:  
                index = j   
                break

        for j in range(index,n-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))
        for j in range(n-2,i-1,-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))        



    print(len(ans))
    for ele in ans:
        print(*ele)



main()


Solution 2 (runtime: 702 ms):
def sol():
    n = int(input())
    a = list(map(int, input().split()))
    rev_a = [None] * n
    for i, x in enumerate(a):
        rev_a[x-1] = i+1
    # print(rev_a)
    steps = []
    orig = list(range(1, n+1))
    for i in range(n):
        x = i + 1
        for p, w in enumerate(rev_a):
            if w == x:
                x_index = p
                break
        
        for j in range(x_index, n-1):
            steps.append((orig[j+1], orig[j]))
            orig[j+1], orig[j] = orig[j], orig[j+1]
            rev_a[j+1], rev_a[j] = rev_a[j], rev_a[j+1]
        for j in range(n-2, x_index-1, -1):
            steps.append((orig[j+1], orig[j]))
            orig[j+1], orig[j] = orig[j], orig[j+1]
            rev_a[j+1], rev_a[j] = rev_a[j], rev_a[j+1]
        if x_index > i:
            for j in range(x_index-1, x-2, -1):
                steps.append((orig[j+1], orig[j]))
                orig[j+1], orig[j] = orig[j], orig[j+1]
                rev_a[j+1], rev_a[j] = rev_a[j], rev_a[j+1]

    print(len(steps))
    for x in steps:
        print(*x)


sol()
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 655 ms):
import io,os
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline




def main():
    n = int(input())
    arr = list(map(int,input().split()))
    for i in range(n):
        arr[i] -= 1


    curr = [i for i in range(n)]

    ans = []


    for i in range(n):
        index = -1
        for j in range(n):
            if curr[j]==arr[i]:  
                index = j   
                break

        for j in range(index,n-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))
        for j in range(n-2,i-1,-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))        



    print(len(ans))
    for ele in ans:
        print(*ele)



main()


Solution 2 (runtime: 999 ms):
import sys
from queue import deque
from bisect import bisect_left, bisect_right
from heapq import *
from collections import *

sys.setrecursionlimit(10**5)

input = lambda: sys.stdin.readline().rstrip('\r\n')
iint = lambda: int(input())
mint = lambda: map(int, input().split())
aint = lambda: list(map(int, input().split()))

MOD = 10**9 + 7

def solve():
    n = iint()
    a = aint()
    rank = [0] * (n + 1)
    for i in range(n):
        rank[a[i]] = i+1
   
    mx_len = n * (n-1) // 2
    curr = list(range(n, 0, -1))
    sq = []
    for i in range(n):
        j = i
        while j>0 and rank[curr[j]] < rank[curr[j-1]]:
            sq.append([curr[j], curr[j-1]])
            curr[j], curr[j-1] = curr[j-1], curr[j]
            mx_len += 1
            j -= 1

    print(mx_len)
    for i in range(1, n+1):
        for j in range(i+1, n+1):
            print(j, i)
    for a, b in sq:
        print(a, b)

solve()
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 655 ms):
import io,os
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline




def main():
    n = int(input())
    arr = list(map(int,input().split()))
    for i in range(n):
        arr[i] -= 1


    curr = [i for i in range(n)]

    ans = []


    for i in range(n):
        index = -1
        for j in range(n):
            if curr[j]==arr[i]:  
                index = j   
                break

        for j in range(index,n-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))
        for j in range(n-2,i-1,-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))        



    print(len(ans))
    for ele in ans:
        print(*ele)



main()


Solution 2 (runtime: 1186 ms):
n = int(input())

a = [int(i) for i in input().split()]

inds = [0 for i in range(n+1)]

for i in range(n):

    inds[a[i]] = i



total = 0

changes = []



l = [i+1 for i in range(n)]

for i in range(n):

    ind = l.index(a[i])



    for j in range(ind+1, n):

        changes.append([l[j], a[i]])

    for j in range(n-1, ind, -1):

        changes.append([a[i], l[j]])



    for j in range(ind-1, i-1, -1):

        changes.append([a[i], l[j]])



    l = [l[ind]] + l[:ind] + l[ind+1:]





print(len(changes))

for i in changes:

    print(*i)
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 655 ms):
import io,os
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline




def main():
    n = int(input())
    arr = list(map(int,input().split()))
    for i in range(n):
        arr[i] -= 1


    curr = [i for i in range(n)]

    ans = []


    for i in range(n):
        index = -1
        for j in range(n):
            if curr[j]==arr[i]:  
                index = j   
                break

        for j in range(index,n-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))
        for j in range(n-2,i-1,-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))        



    print(len(ans))
    for ele in ans:
        print(*ele)



main()


Solution 2 (runtime: 483 ms):
from sys import stdin

input = lambda: stdin.readline().strip()



n = int(input())

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

ans = []



for _ in range(n):

    for i in range(n - 1):

        if a[i] < a[i + 1]:

            ans.append((a[i], a[i + 1]))

            a[i], a[i + 1] = a[i + 1], a[i]

for _ in range(n):

    for i in range(n - 1):

        if a[i] > a[i + 1]:

            ans.append((a[i], a[i + 1]))

            a[i], a[i + 1] = a[i + 1], a[i]

ans.reverse()

print(len(ans))

for x, y in ans:

    print(f'{x} {y}')
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 655 ms):
import io,os
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline




def main():
    n = int(input())
    arr = list(map(int,input().split()))
    for i in range(n):
        arr[i] -= 1


    curr = [i for i in range(n)]

    ans = []


    for i in range(n):
        index = -1
        for j in range(n):
            if curr[j]==arr[i]:  
                index = j   
                break

        for j in range(index,n-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))
        for j in range(n-2,i-1,-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))        



    print(len(ans))
    for ele in ans:
        print(*ele)



main()


Solution 2 (runtime: 2265 ms):
n=int(input())

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

liste=[]

if n==1:

    print(0)

else:

    lcurrent=[]

    lchange=[0]*n

    for i in range(n):

        lcurrent.append(i+1)

    for  i in range(n):

        j=n-1-i

        val=l[j]

        y=lcurrent.index(val)

        if y<j:

            lchange[j]=1

            for k in range(y+1,j+1):

                liste.append((lcurrent[k],val))

                lcurrent[k-1]=lcurrent[k]

            lcurrent[j]=val

        if y>j:

            lchange[j]=1

            for k in range(j,y):

                h=y-k

                liste.append((val,lcurrent[h]))

                lcurrent[h+1]=lcurrent[h]

            lcurrent[j]=val

    

    for  i in range(1,n):

     

        j=n-1-i+1

        

        if  lchange[j]==0:

            liste.append((lcurrent[j],lcurrent[j-1]))

            liste.append((lcurrent[j-1],lcurrent[j]))

    print(len(liste))

    for i in liste:

        a,b=i[0],i[1]

        print(a,b)
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 655 ms):
import io,os
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline




def main():
    n = int(input())
    arr = list(map(int,input().split()))
    for i in range(n):
        arr[i] -= 1


    curr = [i for i in range(n)]

    ans = []


    for i in range(n):
        index = -1
        for j in range(n):
            if curr[j]==arr[i]:  
                index = j   
                break

        for j in range(index,n-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))
        for j in range(n-2,i-1,-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))        



    print(len(ans))
    for ele in ans:
        print(*ele)



main()


Solution 2 (runtime: 1093 ms):

n=int(input())
a=[int(i) for i in input().split()]
res=n*(n-1)//2
j=n
r=[]
for i in range(2,n+1):
    for j in range(1,i):
        r.append([i,j])
b=[None]*n
for i in range(n):
    b[a[i]-1]=i+1
c=[n-i for i in range(n)]

for i in range(n-1):
    for j in range(1,n-i):
        if b[c[j]-1]<b[c[j-1]-1]:
            res+=1
            r.append([c[j],c[j-1]])
            c[j],c[j-1]=c[j-1],c[j]
print(res)
for i in r:
    print(i[0],i[1])
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 655 ms):
import io,os
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline




def main():
    n = int(input())
    arr = list(map(int,input().split()))
    for i in range(n):
        arr[i] -= 1


    curr = [i for i in range(n)]

    ans = []


    for i in range(n):
        index = -1
        for j in range(n):
            if curr[j]==arr[i]:  
                index = j   
                break

        for j in range(index,n-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))
        for j in range(n-2,i-1,-1):
            curr[j],curr[j+1] = curr[j+1],curr[j]
            ans.append((curr[j]+1,curr[j+1]+1))        



    print(len(ans))
    for ele in ans:
        print(*ele)



main()


Solution 2 (runtime: 1311 ms):
import math
mod=1000000007
mod1=998244353
inf=10**18+10

def swap(l1,x,y):
    a=l1[x]
    l1[x]=l1[y]
    l1[y]=a

t=1
for i in range(t):
    n=int(input())
    l1=list(map(int,input().split()))

    ind=[-1]*(n+1)
    for j in range(n):
        ind[l1[j]]=j

    l2=[j+1 for j in range(n)]
    st=set()

    ans=[]
    flag=1
    # print(l1)
    while flag:
        flag=0
        x=-1
        y=-1
        for j in range(n):
            for j1 in range(n-1):
                if l1[j1]<l1[j1+1]:
                    ans.append([l1[j1], l1[j1+1]])
                    swap(l1, j1, j1+1)
                if ind[l2[j1+1]]<ind[l2[j1]] and flag==0 and (l2[j1], l2[j1+1]) not in st:
                    # flag=1
                    x,y=j1, j1+1
                if ind[l2[j1+1]]>ind[l2[j1]]:
                    if (l2[j1], l2[j1+1]) not in st:
                        st.add((l2[j1+1],l2[j1]))
                        st.add((l2[j1],l2[j1+1]))
        # print(l1)
        for j in range(n):
            for j1 in range(n-1-j):
                if l1[j1]>l1[j1+1]:
                    ans.append([l1[j1], l1[j1+1]])
                    swap(l1, j1+1, j1)
        ans.reverse()
        if x!=-1:
            st.add((l2[y], l2[x]))
            # print(l2, ans)
            swap(l2, x, y)

    print(len(ans))
    for j in ans:
        print(*j)
    # print(ans)
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 2484 ms):
import sys

def max_num(order, n):
    counted = set()
    m = 0
    string = ""
    for i in order:
        before = ""
        after = ""
        m += n - len(counted)-1
        for j in reversed(range(1,n+1)):
            if j not in counted and j != i:
                if i < j:
                    m += 1
                    before = f"\n{j} {i}"+before
                before += f"\n{i} {j}"
        string += before + after
        counted.add(i)
    print(f"{m}{string}")
    return m, string

i = 0
for line in sys.stdin.readlines():
    if i==0:
        n = int(line)
    else:
        order = [int(x) for x in line.split(" ")]
        max_num(order, n)
    i+=1

Solution 2 (runtime: 702 ms):
def sol():
    n = int(input())
    c = [0] + list(map(int, input().split()))
    mp = [i for i in range(n + 1)]
    pos = [i for i in range(n + 1)]
    ans = []
    for i in range(1, n + 1):
        for j in range(mp[c[i]] + 1, n + 1):
            ans.append((pos[j], c[i]))
        for j in range(n, mp[c[i]], -1):
            ans.append((c[i], pos[j]))
        for j in range(mp[c[i]] - 1, i - 1, -1):
            ans.append((c[i], pos[j]))
            mp[pos[j]] = j + 1
            pos[j + 1] = pos[j]
    
    print(len(ans))
    for a, b in ans:
        print(a, b)

sol()
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 2484 ms):
import sys

def max_num(order, n):
    counted = set()
    m = 0
    string = ""
    for i in order:
        before = ""
        after = ""
        m += n - len(counted)-1
        for j in reversed(range(1,n+1)):
            if j not in counted and j != i:
                if i < j:
                    m += 1
                    before = f"\n{j} {i}"+before
                before += f"\n{i} {j}"
        string += before + after
        counted.add(i)
    print(f"{m}{string}")
    return m, string

i = 0
for line in sys.stdin.readlines():
    if i==0:
        n = int(line)
    else:
        order = [int(x) for x in line.split(" ")]
        max_num(order, n)
    i+=1

Solution 2 (runtime: 437 ms):
num_cars = int(input())
arr = [int(a) for a in input().split()]
arr.reverse()
running_sum = 0
overtake_list = []
car_list = [i for i in range(1, num_cars + 1)]
car_list.reverse()
for n, i in enumerate(arr):
    curr_index = car_list.index(i)
    car_list.pop(curr_index)
    for elem in (range(curr_index, len(car_list))):
        overtake_list.append(f"{i} {car_list[elem]}")
    for elem in reversed(range(0, len(car_list))):
        overtake_list.append(f"{car_list[elem]} {i}")
    
print(len(overtake_list))
for overtake in overtake_list:
    print(overtake)
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 2484 ms):
import sys

def max_num(order, n):
    counted = set()
    m = 0
    string = ""
    for i in order:
        before = ""
        after = ""
        m += n - len(counted)-1
        for j in reversed(range(1,n+1)):
            if j not in counted and j != i:
                if i < j:
                    m += 1
                    before = f"\n{j} {i}"+before
                before += f"\n{i} {j}"
        string += before + after
        counted.add(i)
    print(f"{m}{string}")
    return m, string

i = 0
for line in sys.stdin.readlines():
    if i==0:
        n = int(line)
    else:
        order = [int(x) for x in line.split(" ")]
        max_num(order, n)
    i+=1

Solution 2 (runtime: 640 ms):
def II():
    return(int(input()))
def LMI():
    return(list(map(int,input().split())))
def I():
    return(input())
def MII():
    return(map(int,input().split()))
# import sys
# input=sys.stdin.readline
# import io,os
# input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline
# from collections import Counter
# int(math.log(len(L)))
# import math
# from collections import defaultdict
# mod=10**9+7
# from collections import deque
# import  math



# from functools import cache
# @cache
def t():
    n=II()
    L=LMI()
    ans=[]
    cur=[i for i in range(1,n+1)]
    for i in range(n):
        ind=cur.index(L[i])
        for j in range(ind+1,n):
            ans.append((cur[j],cur[ind]))
        for j in range(n-1,i-1,-1):
            if j==ind:continue 
            ans.append((cur[ind],cur[j]))
        del cur[ind]
        cur=cur[:i]+[L[i]]+cur[i:]
    print(len(ans))
    for i in ans:
        print(*i)           
    return



if __name__=="__main__":

    # for _ in range(II()):
    #     t()
    t()
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 2484 ms):
import sys

def max_num(order, n):
    counted = set()
    m = 0
    string = ""
    for i in order:
        before = ""
        after = ""
        m += n - len(counted)-1
        for j in reversed(range(1,n+1)):
            if j not in counted and j != i:
                if i < j:
                    m += 1
                    before = f"\n{j} {i}"+before
                before += f"\n{i} {j}"
        string += before + after
        counted.add(i)
    print(f"{m}{string}")
    return m, string

i = 0
for line in sys.stdin.readlines():
    if i==0:
        n = int(line)
    else:
        order = [int(x) for x in line.split(" ")]
        max_num(order, n)
    i+=1

Solution 2 (runtime: 781 ms):
n = int(input())
final_order = [int(x) - 1 for x in input().split()]
cur_order = list(range(n))

swaps = []
for i, target in enumerate(final_order):
    cur_pos = cur_order.index(target)
    for j in range(cur_pos + 1, n):
        swaps.append((cur_order[j], target))
    for j in range(n - 1, i - 1, -1):
        if j == cur_pos:
            continue
        swaps.append((target, cur_order[j]))
    cur_order.pop(cur_pos)
    cur_order.insert(i, target)

print(len(swaps))
for x, y in swaps:
    print(x + 1, y + 1)
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 2484 ms):
import sys

def max_num(order, n):
    counted = set()
    m = 0
    string = ""
    for i in order:
        before = ""
        after = ""
        m += n - len(counted)-1
        for j in reversed(range(1,n+1)):
            if j not in counted and j != i:
                if i < j:
                    m += 1
                    before = f"\n{j} {i}"+before
                before += f"\n{i} {j}"
        string += before + after
        counted.add(i)
    print(f"{m}{string}")
    return m, string

i = 0
for line in sys.stdin.readlines():
    if i==0:
        n = int(line)
    else:
        order = [int(x) for x in line.split(" ")]
        max_num(order, n)
    i+=1

Solution 2 (runtime: 952 ms):
import sys

N = int(sys.stdin.readline())

class Number:
    
    SWAPS = set()
    
    def __init__(self, value, index):
        self.value = value
        self.idx = value-1
        self.final_idx = index
        
    def __repr__(self):
        return str(self.value)
    
    @staticmethod
    def swap(a, b):
        if a == b: return
        if (a, b) in Number.SWAPS: return
        a, b = Number.dct[a], Number.dct[b]
        if a.idx < b.idx: return
        a.idx, b.idx = b.idx, a.idx
        Number.lst[a.idx], Number.lst[b.idx] = a, b
        Number.swaps.append((a.value, b.value))
        Number.SWAPS.add((a.value, b.value))

Number.dct = {int(x): Number(int(x), i) for i, x in enumerate(sys.stdin.readline().split())}
Number.lst = [Number.dct[i] for i in range(1, N + 1)]
Number.swaps = []
            
lst = Number.lst
dct = Number.dct
swaps = Number.swaps

def bring_to_front(n):
    if dct[n].idx == 0: return
    for i in range(n-1, 0, -1):
        Number.swap(n, lst[i-1].value)
        
def bring_to_back(n):
    idx = dct[n].final_idx
    if idx == 0: return
    for i in range(1, idx+1):
        Number.swap(lst[i].value, n)
        
for i in reversed(dct.keys()):
    bring_to_front(i)
    bring_to_back(i)

sys.stdout.write(str(len(swaps)) + '\n')
for swap in swaps:
    sys.stdout.write(str(swap[0]) + ' ' + str(swap[1]) + '\n')
Problem: 2052A - Adrenaline Rush
Language: python

Solution 1 (runtime: 2484 ms):
import sys

def max_num(order, n):
    counted = set()
    m = 0
    string = ""
    for i in order:
        before = ""
        after = ""
        m += n - len(counted)-1
        for j in reversed(range(1,n+1)):
            if j not in counted and j != i:
                if i < j:
                    m += 1
                    before = f"\n{j} {i}"+before
                before += f"\n{i} {j}"
        string += before + after
        counted.add(i)
    print(f"{m}{string}")
    return m, string

i = 0
for line in sys.stdin.readlines():
    if i==0:
        n = int(line)
    else:
        order = [int(x) for x in line.split(" ")]
        max_num(order, n)
    i+=1

Solution 2 (runtime: 2077 ms):
def count(li):
    su = 0
    for i in range(len(li)-1, 0, -1):
        for j in range(i):
            if li[j] > li[i]:
                su += 1
            else:
                su += 2
    return su


n = int(input())
firs = [_ for _ in range(1, n+1)]     #1 2 3 4
fina = list(map(int, input().split()))#2 1 4 3
fina.reverse()
reve = fina.copy()  #第一轮超车后的排序 # 3 4 1 2
fina.reverse()
ans = set() #已经排好的数组
print(count(fina))

for i in range(n):  #2 1 4 3
    for j in range(fina[i]+1, n+1):  #如果有大于他的，就超过他
        if j in ans:       #如果大于他的数已经排好了，就跳过他
            continue
        print(j,fina[i])

    ans.add(fina[i])
for k in range(n-1, 0, -1): # 3 4 1 2
    for t in range(1, k+1):
        print(reve[k], reve[k-t])