Buggy python submission (verdict: Runtime Error):
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        if B != 1:
            a.append(A)
            b.append(B)

    ans = b[-1] - a[-1]%b[-1]
    if a[-1]%b[-1] == 0: ans = 0
    
    for i in range(1, len(a)):
        c = a[-(i+1)]+ans
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans += dis
        else:
            dis = b[-(i+1)] - c
            ans += dis

    return max(0, ans)
    

print(solve())


Fixed submission:
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        a.append(A)
        b.append(B)

    ans = b[-1] - a[-1]%b[-1]
    if a[-1]%b[-1] == 0: ans = 0

    for i in range(1, n):
        c = a[-(i+1)]+ans
        if c%b[-(i+1)] == 0: continue
        
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans += dis
        else:
            dis = b[-(i+1)] - c
            ans += dis

    return max(0, ans)
    

print(solve())

Buggy python submission (verdict: Runtime Error):
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        if B != 1:
            a.append(A)
            b.append(B)

    ans = b[-1] - a[-1]%b[-1]
    for i in range(1, len(a)):
        c = a[-(i+1)]+ans
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans += dis
        else:
            dis = b[-(i+1)] - c
            ans += dis

    return max(0, ans)
    

print(solve())


Fixed submission:
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        a.append(A)
        b.append(B)

    ans = b[-1] - a[-1]%b[-1]
    if a[-1]%b[-1] == 0: ans = 0

    for i in range(1, n):
        c = a[-(i+1)]+ans
        if c%b[-(i+1)] == 0: continue
        
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans += dis
        else:
            dis = b[-(i+1)] - c
            ans += dis

    return max(0, ans)
    

print(solve())

Buggy python submission (verdict: Runtime Error):
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        if B != 1:
            a.append(A)
            b.append(B)

    dis = b[-1] - a[-1]%b[-1]
    ans = [dis]
    for i in range(1, len(a)):
        c = a[-(i+1)]+ans[i-1]
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans.append(ans[i-1]+dis)
        elif c == b[-(i+1)]:
            ans.append(0)
        else:
            dis = c
            ans.append(dis)

    return max(0, ans[-1])
    

print(solve())


Fixed submission:
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        a.append(A)
        b.append(B)

    ans = b[-1] - a[-1]%b[-1]
    if a[-1]%b[-1] == 0: ans = 0

    for i in range(1, n):
        c = a[-(i+1)]+ans
        if c%b[-(i+1)] == 0: continue
        
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans += dis
        else:
            dis = b[-(i+1)] - c
            ans += dis

    return max(0, ans)
    

print(solve())

Buggy python submission (verdict: Runtime Error):
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        if B != 1:
            a.append(A)
            b.append(B)

    dis = b[-1] - a[-1]%b[-1]
    ans = [dis]
    for i in range(1, len(a)):
        c = a[-(i+1)]+ans[i-1]
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans.append(ans[i-1]+dis)
        elif c == b[-(i+1)]:
            ans.append(0)
        else:
            dis = c
            ans.append(dis)

    return max(0, ans[-1])
    

print(solve())


Fixed submission:
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        a.append(A)
        b.append(B)

    ans = b[-1] - a[-1]%b[-1]
    if a[-1]%b[-1] == 0: ans = 0

    for i in range(1, n):
        c = a[-(i+1)]+ans
        if c%b[-(i+1)] == 0: continue
        
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans += dis
        else:
            dis = b[-(i+1)] - c
            ans += dis

    return max(0, ans)
    

print(solve())

Buggy python submission (verdict: Runtime Error):
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        if B != 1:
            a.append(A)
            b.append(B)

    dis = b[-1] - a[-1]%b[-1]
    ans = [dis]
    for i in range(1, len(a)):
        c = a[-(i+1)]+ans[i-1]
        if c >= b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans.append(ans[i-1]+dis)
        else:
            dis = c
            ans.append(dis)

    return max(0, ans[-1])
    

print(solve())


Fixed submission:
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        a.append(A)
        b.append(B)

    ans = b[-1] - a[-1]%b[-1]
    if a[-1]%b[-1] == 0: ans = 0

    for i in range(1, n):
        c = a[-(i+1)]+ans
        if c%b[-(i+1)] == 0: continue
        
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans += dis
        else:
            dis = b[-(i+1)] - c
            ans += dis

    return max(0, ans)
    

print(solve())

Buggy python submission (verdict: Runtime Error):
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        if B != 1:
            a.append(A)
            b.append(B)

    dis = b[-1] - a[-1]%b[-1]
    ans = [dis]
    for i in range(1, len(a)):
        c = a[-(i+1)]+ans[i-1]
        if c >= b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans.append(ans[i-1]+dis)
        else:
            dis = c
            ans.append(dis)

    return ans[-1]
    

print(solve())


Fixed submission:
def solve():
    n = int(input())
    a = []
    b = []
    for _ in range(n):
        A, B = map(int, input().split())
        a.append(A)
        b.append(B)

    ans = b[-1] - a[-1]%b[-1]
    if a[-1]%b[-1] == 0: ans = 0

    for i in range(1, n):
        c = a[-(i+1)]+ans
        if c%b[-(i+1)] == 0: continue
        
        if c > b[-(i+1)]:
            dis = b[-(i+1)]-c%b[-(i+1)]
            ans += dis
        else:
            dis = b[-(i+1)] - c
            ans += dis

    return max(0, ans)
    

print(solve())