Buggy python submission (verdict: Runtime Error):
n = int(input())
P =[]
s = 0
for i in range(n):P.append([int(i) for i in input().split()])
P.append(P[0])
for i in range(n):
    a = P[i][0] ; b = P[i][1]; c = P[i+1][0] ; P[i+1][1]
    s += a * d - b * c
print(abs(s)*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)

Buggy python submission (verdict: Runtime Error):
n = int(input())
P =[]
s = 0
x0,y0 = [int(i) for i in input().split()]
for i in range(n):
    x,y = [int(i) for i in input().split()]
    P.append([x-x0,y-y0])
for i in range(n-2):
    s += P[i][0]*P[i+1][1] - P[i][1]*P[i+1][0]
print(abs(s)*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)

Buggy python submission (verdict: Runtime Error):
n = int(input())
P =[]
s = 0
x,y = 
for _ in range(n):P.append([int(i) for i in input().split()])
P.append(P[0])
for j in range(n):s += P[j][0]*P[j+1][1] - P[j][1]*P[j+1][0]
print(s*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)

Buggy python submission (verdict: Runtime Error):
n = int(input())
P =[]
s = 0
for _ in range(n):P.append([int(-i) for i in input().split()])
P.append(P[0])
for j in range(n):s += P[j][1]*P[j+1][0] -  P[j][0] * P[j+1][1]
print(s*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)

Buggy python submission (verdict: Runtime Error):
n = int(input())
x = range(n)
P =[]
s = 0
for _ in x:P += [int(i) for i in input().split()]
P+=P[0]
for j in x:s += P[j][0]*P[j+1][1] - P[j][1]*P[j+1][0]
print(s*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)

Buggy python submission (verdict: Runtime Error):
n = int(input())
x = range(n)
P =[]
s = 0
for _ in x:P += [[int(i) for i in input().split()]]
P+=P[0]
for j in x:s += P[j][0]*P[j+1][1] - P[j][1]*P[j+1][0]
print(s*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)

Buggy python submission (verdict: Runtime Error):
n = int(input())
x = range(n)
P =[]
s = 0
for _ in x:P.append([int(i) for i in input().split()])
P+=P[0]
for j in x:s += P[j][0]*P[j+1][1] - P[j][1]*P[j+1][0]
print(s*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)

Buggy python submission (verdict: Runtime Error):
n = int(input())
x = range(n)
P =[]
s = 0
for _ in x:P += [[int(i) for i in input().split()]]
P+=P[0]
for j in x:s += P[j][0]*P[j+1][1] - P[j][1]*P[j+1][0]
print(s*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)

Buggy python submission (verdict: Runtime Error):
x=range(int(input()))
P=[]
_=0
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:s+=P[j][0]*P[j+1][1]-P[j][1]*P[j+1][0]
print(s*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)

Buggy python submission (verdict: Runtime Error):
x=range(int(input()))
f=lambda a,b,c,d : a*d - b*c 
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
_=0
P+=[P[0]]
for j in x:_+=f(P[j][0],P[j][1],,P[j+1][0]P[j+1][1])
print(_*0.5)

Fixed submission:
x=range(int(input())-1,-1,-1)
P=[]
for _ in x:P+=[[int(i) for i in input().split()]]
P+=[P[0]]
for j in x:_+=P[j+1][1]*P[j][0]-P[j][1]*P[j+1][0]
print(_*0.5)