Buggy python submission (verdict: Time Limit Exceeded):
from itertools import combinations

def count(x1,y1,x2,y2):
    res = 0
    for i in range(N):
        s1 = x[i]
        s2 = y[i]
        if x1 <= s1 <= x2 and y1 <= s2 <= y2:
            res += 1
    return res 

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

x = []
y = []
y_dict = {}

for i in range(N):
    a,b = map(int,input().split())
    x.append(a)
    y.append(b)
    y_dict[a] = b

number = [i for i in range(N)]
x_2 = sorted(x)
ans = 10**20

for i,j in list(combinations(number,2)):
#for i in range(len(x_2)-1):#長方系の左の辺をx座標を取得し,固定
#    for j in range(i+1,len(x_2)):#長方形の右の辺のx座標を取得し,固定

    y_list = []

    for k in range(i,j+1):#xの指定区間内にある点のy座標を取得しy_listに入れる
        y_list.append(y_dict[x_2[k]])
        
    y_list = sorted(y_list)
        

    if 2 <= len(y_list):
        #for l in range(len(y_list)-1):#yの大きい値から順に組み合わせを試す
            #for m in range(l+1,len(y_list)):
        number2 = [i for i in range(len(y_list))]
        for l,m in list(combinations(number2,2)):        
                x1 = x_2[i]
                y1 = y_list[l]
                x2 = x_2[j]
                y2 = y_list[m]
                point = count(x1,y1,x2,y2)#区間内の点の数
                
                    
                if K <= point :
                    ans = min(ans,(x2-x1)*(y2-y1)) 


               
print(ans)

Fixed submission:
from itertools import combinations as comb

def count(x1,y1,x2,y2):
    res = 0
    for x,y in point:
        if x1 <= x <= x2 and y1 <= y <= y2:
            res += 1
    return res 
    
N,K = map(int,input().split())

x = []
point = []
y_dict = {}

for i in range(N):
    a,b = map(int,input().split())
    x.append(a)
    point.append((a,b))
    y_dict[a] = b#yの値はxの値と紐づけしておく

x = sorted(x)
ans = 10**20

number = [i for i in range(N)]
C = list(comb(number,2))

for i,j in C:#組合せで調べる
    y_list = []

    for k in range(i,j+1):#xの指定区間内にある点のy座標を取得しy_listに入れる
        y_list.append(y_dict[x[k]])
        
    y_list = sorted(y_list)
        

    if 2 <= len(y_list):
        number2 = [i for i in range(len(y_list))]
        C_2 = list(comb(number2,2))

        for l,m in C_2:        
                x1 = x[i]
                y1 = y_list[l]
                x2 = x[j]
                y2 = y_list[m]
                n = count(x1,y1,x2,y2)#区間内の点の数
                   
                if K <= n :
                    ans = min(ans,(x2-x1)*(y2-y1)) 
               
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
def count(x1,y1,x2,y2):
    res = 0
    for i in range(N):
        s1 = x[i]
        s2 = y[i]
        if x1 <= s1 <= x2 and y1 <= s2 <= y2:
            res += 1
    return res 

    
N,K = map(int,input().split())
x = []
y = []
y_dict = {}
for i in range(N):
    a,b = map(int,input().split())
    x.append(a)
    y.append(b)
    y_dict[a] = b
x_2 = sorted(x)
y_2 = sorted(y)
ans = 10**20

for i in range(len(x_2)-1):#長方系の左の辺をx座標を取得し,固定
    for j in range(i+1,len(x_2)):#長方形の右の辺のx座標を取得し,固定

        y_list = []

        for k in range(i,j+1):#区間内にある点のy座標を取得しy_listに入れる
            y_list.append(y_dict[x_2[k]])
        
        y_list = sorted(y_list)
        

        if 2 <= len(y_list):
            for l in range(len(y_list)-1):#yの大きい値から順に組み合わせを試す
                for m in range(l+1,len(y_list)):
                
                    x1 = x_2[i]
                    y1 = y_list[l]
                    x2 = x_2[j]
                    y2 = y_list[m]
                    point = count(x1,y1,x2,y2)#区間内の点の数
                    
                    
                    if K <= point :
                        ans = min(ans,(x2-x1)*(y2-y1)) 


               
print(ans) 

Fixed submission:
from itertools import combinations as comb

def count(x1,y1,x2,y2):
    res = 0
    for x,y in point:
        if x1 <= x <= x2 and y1 <= y <= y2:
            res += 1
    return res 
    
N,K = map(int,input().split())

x = []
point = []
y_dict = {}

for i in range(N):
    a,b = map(int,input().split())
    x.append(a)
    point.append((a,b))
    y_dict[a] = b#yの値はxの値と紐づけしておく

x = sorted(x)
ans = 10**20

number = [i for i in range(N)]
C = list(comb(number,2))

for i,j in C:#組合せで調べる
    y_list = []

    for k in range(i,j+1):#xの指定区間内にある点のy座標を取得しy_listに入れる
        y_list.append(y_dict[x[k]])
        
    y_list = sorted(y_list)
        

    if 2 <= len(y_list):
        number2 = [i for i in range(len(y_list))]
        C_2 = list(comb(number2,2))

        for l,m in C_2:        
                x1 = x[i]
                y1 = y_list[l]
                x2 = x[j]
                y2 = y_list[m]
                n = count(x1,y1,x2,y2)#区間内の点の数
                   
                if K <= n :
                    ans = min(ans,(x2-x1)*(y2-y1)) 
               
print(ans)