Buggy python submission (verdict: Runtime Error):
def cnct(lint,lim):
    global list753
    global list357
    global list333
    lint1=str(lint)+"3"
    lint1int=int(lint1)
    if lint1int<=lim and not lint1int in list357:
        list357.add(lint1int)
        cnct(lint1int,lim)
    lint2=str(lint)+"5"
    lint2int=int(lint2)
    if lint2int<=lim and not lint2int in list357:
        list357.add(lint2int)
        cnct(lint2int,lim)
    lint3=str(lint)+"7"
    lint3int=int(lint3)
    if lint3int<=lim and not lint3int in list357:
        list357.add(lint3int)
        cnct(lint3int,lim) 
    lint4="3"+str(lint)
    lint4int=int(lint4)
    if lint4int<=lim and not lint4int in list357:
        list357.add(lint4int)
        cnct(lint4int,lim)
    lint5="5"+str(lint)
    lint5int=int(lint5)
    if lint5int<=lim and not lint5int in list357:
        list357.add(lint5int)
        cnct(lint5int,lim)
    lint6="7"+str(lint)
    lint6int=int(lint6)
    if lint6int<=lim and not lint6int in list357:
        list357.add(lint6int)
        cnct(lint6int,lim)
def D(lint):
    lista=list(str(lint))
    if lista.count("3") and lista.count("5") and lista.count("7"):
        return True
    else:
        return False

list753=[3,5,7]
list357=set()
k=int(input())
count=0
for b in list753:
    cnct(b,k)
list333=list(list357)
list333.sort()
for c in [x for x in list333]:
    if not D(c):
        list333.remove(c)
print(len(list333))

Fixed submission:
class Number:
    def __init__(self,number,qty):
        self.qty=qty
        self.number=number

n,k=map(int,input().split())
listn=[]
for a in range(n):
    b,c=map(int,input().split())
    listn.append(Number(b,c))
listn.sort(key=lambda x:x.number)
count=k
for a in listn:
    if a.qty>=count:
        print(a.number)
        break
    else:
        count-=a.qty

Buggy python submission (verdict: Runtime Error):
def cnct(lint,lim):
    global list753
    global list357
    global list333
    lint1=str(lint)+"3"
    lint1int=int(lint1)
    if lint1int<=lim and not lint1int in list357:
        list357.add(lint1int)
        cnct(lint1int,lim)
    lint2=str(lint)+"5"
    lint2int=int(lint2)
    if lint2int<=lim and not lint2int in list357:
        list357.add(lint2int)
        cnct(lint2int,lim)
    lint3=str(lint)+"7"
    lint3int=int(lint3)
    if lint3int<=lim and not lint3int in list357:
        list357.add(lint3int)
        cnct(lint3int,lim) 
    lint4="3"+str(lint)
    lint4int=int(lint4)
    if lint4int<=lim and not lint4int in list357:
        list357.add(lint4int)
        cnct(lint4int,lim)
    lint5="5"+str(lint)
    lint5int=int(lint5)
    if lint5int<=lim and not lint5int in list357:
        list357.add(lint5int)
        cnct(lint5int,lim)
    lint6="7"+str(lint)
    lint6int=int(lint6)
    if lint6int<=lim and not lint6int in list357:
        list357.add(lint6int)
        cnct(lint6int,lim)
def D(lint):
    lista=list(str(lint))
    if lista.count("3") and lista.count("5") and lista.count("7"):
        return True
    else:
        return False

list753=[3,5,7]
list357=set()
k=int(input())
count=0
for b in list753:
    cnct(b,k)
list333=list(list357)
list333.sort()
for c in [x for x in list333]:
    if not D(c):
        list333.remove(c)
print(len(list333))

Fixed submission:
class Number:
    def __init__(self,number,qty):
        self.qty=qty
        self.number=number

n,k=map(int,input().split())
listn=[]
for a in range(n):
    b,c=map(int,input().split())
    listn.append(Number(b,c))
listn.sort(key=lambda x:x.number)
count=k
for a in listn:
    if a.qty>=count:
        print(a.number)
        break
    else:
        count-=a.qty

Buggy python submission (verdict: Runtime Error):
%%cython
n,k=map(int,input().split())
listn=[]
for a in range(n):
    b,c=map(int,input().split())
    listn+=[b]*c
listn.sort()
print(listn[k-1])

Fixed submission:
class Number:
    def __init__(self,number,qty):
        self.qty=qty
        self.number=number

n,k=map(int,input().split())
listn=[]
for a in range(n):
    b,c=map(int,input().split())
    listn.append(Number(b,c))
listn.sort(key=lambda x:x.number)
count=k
for a in listn:
    if a.qty>=count:
        print(a.number)
        break
    else:
        count-=a.qty

Buggy python submission (verdict: Time Limit Exceeded):
n,k=map(int,input().split())
listn=[]
for a in range(n):
    b,c=map(int,input().split())
    listn+=[b]*c
listn.sort()
print(listn[k-1])

Fixed submission:
class Number:
    def __init__(self,number,qty):
        self.qty=qty
        self.number=number

n,k=map(int,input().split())
listn=[]
for a in range(n):
    b,c=map(int,input().split())
    listn.append(Number(b,c))
listn.sort(key=lambda x:x.number)
count=k
for a in listn:
    if a.qty>=count:
        print(a.number)
        break
    else:
        count-=a.qty

Buggy python submission (verdict: Time Limit Exceeded):
n,k=map(int,input().split())
listn=[]
for a in range(n):
    b,c=map(int,input().split())
    listn+=[b]*c
listn.sort()
print(listn[k-1])

Fixed submission:
class Number:
    def __init__(self,number,qty):
        self.qty=qty
        self.number=number

n,k=map(int,input().split())
listn=[]
for a in range(n):
    b,c=map(int,input().split())
    listn.append(Number(b,c))
listn.sort(key=lambda x:x.number)
count=k
for a in listn:
    if a.qty>=count:
        print(a.number)
        break
    else:
        count-=a.qty