I am trying to remove lines that start with/contain only integers.

So for example this input file:

15
Humpty Dumpty
12
sat on a
5
wall

Should be ouput to a file like so:

Humpty Dumpty
sat on a
wall

I have tried the following:

Code:
 string line;
 while (INFILE)
 {
  getline(INFILE, line) ;
  
  if(line[0] == '0' || '1' || '2' || '3' || '4' || '5' || '6' || '7' || '8' || '9')
  {
   line.clear() ;
  }
Basically what I am trying to achieve is to read a line from an input file. If that line starts with integers, remove it somehow and continue to the next line. If a line does not have any integers in it, output it to the output file. I have tried doing this with a for loop to go through the entire string, but it did not work as I thought it would. Anyway, I am stuck and would greatly appreciate any help. Thanks.