s = input().strip()
k = int(input())
a = list(s)
n = len(a)
for i in range(n - 1):
m = i
for j in range(i + 1, n):
if a[j] < a[m]:
m = j
a[i], a[m] = a[m], a[i]
print(a[k-1])
cyA9IGlucHV0KCkuc3RyaXAoKQprID0gaW50KGlucHV0KCkpCgphID0gbGlzdChzKQpuID0gbGVuKGEpCmZvciBpIGluIHJhbmdlKG4gLSAxKToKICAgIG0gPSBpCiAgICBmb3IgaiBpbiByYW5nZShpICsgMSwgbik6CiAgICAgICAgaWYgYVtqXSA8IGFbbV06CiAgICAgICAgICAgIG0gPSBqCiAgICBhW2ldLCBhW21dID0gYVttXSwgYVtpXQpwcmludChhW2stMV0p