Data name is cardnumbers.txt
data here
4120670000624855
4266901024841678
6011002543517833
6011208947684752
5545141002153628
4403190016296308
6011208997992451
8466160241276433
4313072843714489
5121079602112358
4403190015929676
5581588012277612
5466160341276433
4313072843777890
this is my coding down here I did exactly what book showed but doesn't work it doesn't read file. And yes I put text file same place as cpp file.