n = int(input())
s = input()
sr = (n + 1) // 2
uk1 = sr
uk2 = n - sr
while(1):
    uk2 = n - uk1
    f1 = 0
    f2 = 0
    a11 = 0
    a21 = 0
    a12 = 0
    a22 = 0
    if (s[uk1] != '0'):
        f1 = 1
        for i in range(0, uk1):
            a11 = a11 * 10 + (ord(s[i]) - ord('0'))
        for i in range(uk1, len(s)):
            a21 = a21 * 10 + (ord(s[i]) - ord('0'))
    uk1, uk2 = uk2, uk1
    if (s[uk1] != '0'):
        f2 = 1
        for i in range(0, uk1):
            a12 = a12 * 10 + (ord(s[i]) - ord('0'))
        for i in range(uk1, len(s)):
            a22 = a22 * 10 + (ord(s[i]) - ord('0'))
    if (f1 == 1 and f2 == 0):
        print(a11 + a21)
        exit(0)
    if (f1 == 0 and f2 == 1):
        print(a12 + a22)
        exit(0)
    if (f1 == 1 and f2 == 1):
        print(min(a11 + a21, a12 + a22))
        exit(0)
    uk1, uk2 = uk2, uk1
    uk1 -= 1
print(1 / 0)