문제
https://www.acmicpc.net/problem/1748
풀이

코드
def answer():
global n
i, ans = (1, 0)
while(i < len(str(n))+1):
if n >= 10**i:
ans += i*(((10**i)-1) - 10**(i-1) + 1)
else:
ans += i*(n - 10**(i-1) + 1)
i += 1
print(ans)
n = int(input())
answer()