运行时错误，但代码可用于测试输入

Question

该代码可以很好地处理示例值，但在Hackerrank上提交时显示运行时错误。请帮忙

n=int(input())
marksheet=[]
minimum=[]
for i in range(n):
    name=input()
    score=float(input())
    marksheet.append([name,score])
last=(min(marksheet, key=lambda x:x[1]))
for i in range(n):
    clast=min(marksheet,key=lambda x:x[1])
    if last==clast:
        marksheet.pop()
last2=(min(marksheet,key=lambda x:x[1]))
minimum.append(last2)
marksheet.remove(min(marksheet,key=lambda x:x[1]))
for i in range (len(marksheet)):
    clast2=min(marksheet,key=lambda x:x[1])
    if last2[1]==clast2[1]:
        minimum.append(clast2)
    marksheet.remove(min(marksheet,key=lambda x:x[1]))
minimum.sort()
for item in minimum:
    print (item[0])