题解 | #提取数字电话#

strs = input()
tiqu = list()
for i in strs:
    if(i == '0' or i == '1' or i == '2' or i == '3' or i == '4' or i == '5' or i == '6' or i == '7' or i == '8' or i == '9'):
        tiqu.append(i)
    else:
        continue

for i in tiqu:
    print(i,end='')