A Telephone Bill in Slabs

Read the customer's name as a whole line, which may contain spaces, then the number of units used as an integer on the next line, and print the bill. The first 100 units cost 95 paise each, the next 75 units cost Rs 1.50 each, and every unit beyond 175 costs Rs 2.85. Every customer pays a service charge of Rs 75. If the total amount, call charge plus service charge, is more than Rs 500, add a surcharge of 12.5% of that total. Print six lines in exactly this form: name: Asha Rao, units consumed: 200, call charge: 278.75, service charge: 75.00, surcharge: 0.00, total amount: 353.75, with every amount to two decimal places. Read the name with fgets and remove the trailing newline. If the units are negative print units cannot be negative and return 1. If the name or the units cannot be read print invalid input and return 1.