Standard input is empty

Standard output is empty

./prog.sh: line 1: https://v...content-available-to-author-only...s.com/files/f24rwxQ41D3KOhQje5nqvQ7NKpQqIo3ay0aIQSrk.pdf: No such file or directory
./prog.sh: line 2: https://v...content-available-to-author-only...s.com/files/W2nuUTl3Lkm7zp81SrwmLenH6rctWYvhZE5S3IMn.pdf: No such file or directory
./prog.sh: line 3: https://v...content-available-to-author-only...s.com/files/KnQrHhPntrR28uAxG2NcFcmOo64ksY6omrzdBazq.pdf: No such file or directory
./prog.sh: line 4: https://v...content-available-to-author-only...s.com/files/EuLQAcqIixYeAnlaj5POiqfn5ToUNdnUk4j1rOgA.pdf: No such file or directory
./prog.sh: line 5: https://v...content-available-to-author-only...s.com/files/dHyBTHONmDQ70cxjl6xUa4K4SQWcOGsPnS0K2wU6.pdf: No such file or directory
./prog.sh: line 6: https://v...content-available-to-author-only...s.com/files/TrlN8FBlPASzLL7sxzLR6fZ1LZVWm28zRz6vq0O3.pdf: No such file or directory
./prog.sh: line 7: https://v...content-available-to-author-only...s.com/files/as7KpIrnnPdsdL4g78Vj2F2qkTgKVVMtPqCMkVFZ.pdf: No such file or directory
./prog.sh: line 8: https://v...content-available-to-author-only...s.com/files/hGeMa54H0TnE0HncV4giqn3melezIVxnD7HCwInj.pdf: No such file or directory
./prog.sh: line 9: https://p...content-available-to-author-only...o.com/xUrBzLydYPux: No such file or directory
./prog.sh: line 10: https://w...content-available-to-author-only...e.com/page/303983/srwqscdhrtgefds: No such file or directory
./prog.sh: line 11: https://d...content-available-to-author-only...t.org/paste/de3de9ff: No such file or directory
./prog.sh: line 12: https://a...content-available-to-author-only...e.com/paste/de3de9ff: No such file or directory