rt，ABC379 E

n=int(input())
ss=input()
s=int(ss)

bi=1
for i in range(1, n):
    bi=bi*10+1

f = 0
now = 0
for num in ss:
    now = now*10 + int(num)
    f += now

ans=0
for idx, num in enumerate(ss):
    ans += f
    f -= int(num)*bi
    bi//=10

print(ans)