Buggy python submission (verdict: Time Limit Exceeded):
N,K = map(int,input().split())
XY = [list(map(int,input().split())) for i in range(N)]

ans = float("inf")
import itertools
I = [i for i in range(N)]

for B in itertools.combinations(I,4):
    i,j,k,kk = B
    x1,y1 = XY[i]
    x2,y2 = XY[j]
    x3,y3 = XY[k]
    x4,y4 = XY[kk]
    u = max(y1,y2,y3,y4)
    d = min(y1,y2,y3,y4)
    r = max(x1,x2,x3,x4)
    l = min(x1,x2,x3,x4)
    num = 0
    for m in range(N):
        x,y = XY[m]
        if l<=x<=r and d<=y<=u:
            num += 1
    if num >= K:
        tmp = (u-d)*(r-l)
        if tmp < ans:
            ans = tmp
for B in itertools.combinations(I,3):
    i,j,k = B
    x1,y1 = XY[i]
    x2,y2 = XY[j]
    x3,y3 = XY[k]
    u = max(y1,y2,y3)
    d = min(y1,y2,y3)
    r = max(x1,x2,x3)
    l = min(x1,x2,x3)
    num = 0
    for m in range(N):
        x,y = XY[m]
        if l<=x<=r and d<=y<=u:
            num += 1
    if num >= K:
        tmp = (u-d)*(r-l)
        if tmp < ans:
            ans = tmp
for B in itertools.combinations(I,2):
    i,j = B
    x1,y1 = XY[i]
    x2,y2 = XY[j]
    u = max(y1,y2)
    d = min(y1,y2)
    r = max(x1,x2)
    l = min(x1,x2)
    num = 0
    for m in range(N):
        x,y = XY[m]
        if l<=x<=r and d<=y<=u:
            num += 1
    if num >= K:
        tmp = (u-d)*(r-l)
        if tmp < ans:
            ans = tmp
print(ans)

Fixed submission:
N,K = map(int,input().split())
XY = [list(map(int,input().split())) for i in range(N)]

ans = float("inf")
for i in range(N):
    x1,y1 = XY[i]
    for j in range(i+1,N):
        x2,y2 = XY[j]
        u2 = max(y1,y2)
        d2 = min(y1,y2)
        r2 = max(x1,x2)
        l2 = min(x1,x2)
        for k in range(j+1,N):
            x3,y3 = XY[k]
            u3 = max(u2,y3)
            d3 = min(d2,y3)
            r3 = max(r2,x3)
            l3 = min(l2,x3)
            for kk in range(k+1,N):
                x4,y4 = XY[kk]
                u4 = max(u3,y4)
                d4 = min(d3,y4)
                r4 = max(r3,x4)
                l4 = min(l3,x4)
                num = 0
                for m in range(N):
                    x,y = XY[m]
                    if l4<=x<=r4 and d4<=y<=u4:
                        num += 1
                if num >= K:
                    tmp = (u4-d4)*(r4-l4)
                    if tmp < ans:
                        ans = tmp
            num = 0
            for m in range(N):
                x,y = XY[m]
                if l3<=x<=r3 and d3<=y<=u3:
                    num += 1
            if num >= K:
                tmp = (u3-d3)*(r3-l3)
                if tmp < ans:
                    ans = tmp
        num = 0
        for m in range(N):
            x,y = XY[m]
            if l2<=x<=r2 and d2<=y<=u2:
                num += 1
        if num >= K:
            tmp = (u2-d2)*(r2-l2)
            if tmp < ans:
                ans = tmp
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
N,K = map(int,input().split())
XY = [list(map(int,input().split())) for i in range(N)]

ans = float("inf")
for i in range(N):
    for j in range(i+1,N):
        for k in range(j+1,N):
            for kk in range(k+1,N):
                x1,y1 = XY[i]
                x2,y2 = XY[j]
                x3,y3 = XY[k]
                x4,y4 = XY[kk]
                u = max(y1,y2,y3,y4)
                d = min(y1,y2,y3,y4)
                r = max(x1,x2,x3,x4)
                l = min(x1,x2,x3,x4)
                num = 0
                for m in range(N):
                    x,y = XY[m]
                    if l<=x<=r and d<=y<=u:
                        num += 1
                if num >= K:
                    tmp = (u-d)*(r-l)
                    if tmp < ans:
                        ans = tmp
        for k in range(j+1,N):
            x1,y1 = XY[i]
            x2,y2 = XY[j]
            x3,y3 = XY[k]
            u = max(y1,y2,y3)
            d = min(y1,y2,y3)
            r = max(x1,x2,x3)
            l = min(x1,x2,x3)
            num = 0
            for m in range(N):
                x,y = XY[m]
                if l<=x<=r and d<=y<=u:
                    num += 1
            if num >= K:
                tmp = (u-d)*(r-l)
                if tmp < ans:
                    ans = tmp
        x1,y1 = XY[i]
        x2,y2 = XY[j]
        u = max(y1,y2)
        d = min(y1,y2)
        r = max(x1,x2)
        l = min(x1,x2)
        num = 0
        for m in range(N):
            x,y = XY[m]
            if l<=x<=r and d<=y<=u:
                num += 1
        if num >= K:
            tmp = (u-d)*(r-l)
            if tmp < ans:
                ans = tmp
print(ans)

Fixed submission:
N,K = map(int,input().split())
XY = [list(map(int,input().split())) for i in range(N)]

ans = float("inf")
for i in range(N):
    x1,y1 = XY[i]
    for j in range(i+1,N):
        x2,y2 = XY[j]
        u2 = max(y1,y2)
        d2 = min(y1,y2)
        r2 = max(x1,x2)
        l2 = min(x1,x2)
        for k in range(j+1,N):
            x3,y3 = XY[k]
            u3 = max(u2,y3)
            d3 = min(d2,y3)
            r3 = max(r2,x3)
            l3 = min(l2,x3)
            for kk in range(k+1,N):
                x4,y4 = XY[kk]
                u4 = max(u3,y4)
                d4 = min(d3,y4)
                r4 = max(r3,x4)
                l4 = min(l3,x4)
                num = 0
                for m in range(N):
                    x,y = XY[m]
                    if l4<=x<=r4 and d4<=y<=u4:
                        num += 1
                if num >= K:
                    tmp = (u4-d4)*(r4-l4)
                    if tmp < ans:
                        ans = tmp
            num = 0
            for m in range(N):
                x,y = XY[m]
                if l3<=x<=r3 and d3<=y<=u3:
                    num += 1
            if num >= K:
                tmp = (u3-d3)*(r3-l3)
                if tmp < ans:
                    ans = tmp
        num = 0
        for m in range(N):
            x,y = XY[m]
            if l2<=x<=r2 and d2<=y<=u2:
                num += 1
        if num >= K:
            tmp = (u2-d2)*(r2-l2)
            if tmp < ans:
                ans = tmp
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
N,K = map(int,input().split())
XY = [list(map(int,input().split())) for i in range(N)]

ans = float("inf")
for i in range(N):
    for j in range(i+1,N):
        for k in range(j+1,N):
            for kk in range(k+1,N):
                x1,y1 = XY[i]
                x2,y2 = XY[j]
                x3,y3 = XY[k]
                x4,y4 = XY[kk]
                u = max(y1,y2,y3,y4)
                d = min(y1,y2,y3,y4)
                r = max(x1,x2,x3,x4)
                l = min(x1,x2,x3,x4)
                num = 0
                for m in range(N):
                    x,y = XY[m]
                    if l<=x<=r and d<=y<=u:
                        num += 1
                if num >= K:
                    tmp = (u-d)*(r-l)
                    if tmp < ans:
                        ans = tmp
        for k in range(j+1,N):
            x1,y1 = XY[i]
            x2,y2 = XY[j]
            x3,y3 = XY[k]
            u = max(y1,y2,y3)
            d = min(y1,y2,y3)
            r = max(x1,x2,x3)
            l = min(x1,x2,x3)
            num = 0
            for m in range(N):
                x,y = XY[m]
                if l<=x<=r and d<=y<=u:
                    num += 1
            if num >= K:
                tmp = (u-d)*(r-l)
                if tmp < ans:
                    ans = tmp
        x1,y1 = XY[i]
        x2,y2 = XY[j]
        u = max(y1,y2)
        d = min(y1,y2)
        r = max(x1,x2)
        l = min(x1,x2)
        num = 0
        for m in range(N):
            x,y = XY[m]
            if l<=x<=r and d<=y<=u:
                num += 1
        if num >= K:
            tmp = (u-d)*(r-l)
            if tmp < ans:
                ans = tmp
print(ans)

Fixed submission:
N,K = map(int,input().split())
XY = [list(map(int,input().split())) for i in range(N)]

ans = float("inf")
for i in range(N):
    x1,y1 = XY[i]
    for j in range(i+1,N):
        x2,y2 = XY[j]
        u2 = max(y1,y2)
        d2 = min(y1,y2)
        r2 = max(x1,x2)
        l2 = min(x1,x2)
        for k in range(j+1,N):
            x3,y3 = XY[k]
            u3 = max(u2,y3)
            d3 = min(d2,y3)
            r3 = max(r2,x3)
            l3 = min(l2,x3)
            for kk in range(k+1,N):
                x4,y4 = XY[kk]
                u4 = max(u3,y4)
                d4 = min(d3,y4)
                r4 = max(r3,x4)
                l4 = min(l3,x4)
                num = 0
                for m in range(N):
                    x,y = XY[m]
                    if l4<=x<=r4 and d4<=y<=u4:
                        num += 1
                if num >= K:
                    tmp = (u4-d4)*(r4-l4)
                    if tmp < ans:
                        ans = tmp
            num = 0
            for m in range(N):
                x,y = XY[m]
                if l3<=x<=r3 and d3<=y<=u3:
                    num += 1
            if num >= K:
                tmp = (u3-d3)*(r3-l3)
                if tmp < ans:
                    ans = tmp
        num = 0
        for m in range(N):
            x,y = XY[m]
            if l2<=x<=r2 and d2<=y<=u2:
                num += 1
        if num >= K:
            tmp = (u2-d2)*(r2-l2)
            if tmp < ans:
                ans = tmp
print(ans)