Buggy python submission (verdict: Runtime Error):
def readQuestion(a,b):
    a,b=map(int,input().split())

# 解く
def solve(x):
    a,b=map(int,input().split())
    x=[]
    y=0
    high=0
    z=0
    u=0
    for i in range(1,1000):
        y+=i
        x.append(y)
    high = b-a
    z=high-1
    u=x[z]-b
    return u

# 全体
def main():
    x = readQuestion(a,b)
    answer = solve(x)
    print(answer)

# mainを呼び出す
if __name__ == '__main__':
    main()

Fixed submission:
import sys
def readQuestion():
    line = sys.stdin.readline()
    sline = line.rstrip()
    [rline,r1line]=sline.split(" ")
    a=int(rline)
    b=int(r1line)
    return a,b 

def solve(a,b):
    x=[]
    y=0
    high=0
    z=0
    u=0
    for i in range(1,1000):
        y+=i
        x.append(y)
    high = b-a
    z=high-1
    u=x[z]-b
    return u
# 全体
def main():
    x,y = readQuestion()
    answer = solve(x, y)
    print(answer)

# mainを呼び出す
if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
# 問題データを読み込む
def readQuestion(a,b):
    a,b=map(int,input().split())

# 解く
def solve(x):
    a,b=map(int,input().split())
    x=[]
    y=0
    high=0
    z=0
    u=0
    for i in range(1,1000):
        y+=i
        x.append(y)
    high = b-a
    z=high-1
    u=x[z]-b
    print(u)

# 全体
def main():
    x = readQuestion(a,b)
    answer = solve(x)
    print(answer)

# mainを呼び出す
if __name__ == '__main__':
    main()

Fixed submission:
import sys
def readQuestion():
    line = sys.stdin.readline()
    sline = line.rstrip()
    [rline,r1line]=sline.split(" ")
    a=int(rline)
    b=int(r1line)
    return a,b 

def solve(a,b):
    x=[]
    y=0
    high=0
    z=0
    u=0
    for i in range(1,1000):
        y+=i
        x.append(y)
    high = b-a
    z=high-1
    u=x[z]-b
    return u
# 全体
def main():
    x,y = readQuestion()
    answer = solve(x, y)
    print(answer)

# mainを呼び出す
if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
a,b=map(int,input().split())
y=0
high=0
for i in range(1,1000):
    y+=i
    x.append(y)
for xz in x:
    if xz <= b:
        high=xz
        d=high-a
print(d)

Fixed submission:
import sys
def readQuestion():
    line = sys.stdin.readline()
    sline = line.rstrip()
    [rline,r1line]=sline.split(" ")
    a=int(rline)
    b=int(r1line)
    return a,b 

def solve(a,b):
    x=[]
    y=0
    high=0
    z=0
    u=0
    for i in range(1,1000):
        y+=i
        x.append(y)
    high = b-a
    z=high-1
    u=x[z]-b
    return u
# 全体
def main():
    x,y = readQuestion()
    answer = solve(x, y)
    print(answer)

# mainを呼び出す
if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
a,b=map(int,input().split())
y=0
high=0
for i in range(1,1000):
    y+=i
    x.append(y)
for xz in x:
    if xz < b:
        high=xz
print(high-a)

Fixed submission:
import sys
def readQuestion():
    line = sys.stdin.readline()
    sline = line.rstrip()
    [rline,r1line]=sline.split(" ")
    a=int(rline)
    b=int(r1line)
    return a,b 

def solve(a,b):
    x=[]
    y=0
    high=0
    z=0
    u=0
    for i in range(1,1000):
        y+=i
        x.append(y)
    high = b-a
    z=high-1
    u=x[z]-b
    return u
# 全体
def main():
    x,y = readQuestion()
    answer = solve(x, y)
    print(answer)

# mainを呼び出す
if __name__ == '__main__':
    main()