We want to make a simple calculator that can add and subtract integers and will accept arbitrarily long mathematical formulas composed of symbols +, -, and non-negative integer numbers. Imagine you have a file formula. txt with the summation formula such as:100 + 50 - 25 + 0 + 123 - 1If you redirect the file into your program, it should compute and print the $ ./calc < formula. txt247Specifically, write a program calc. cpp that reads from the cin a sequence of one or more non-negative integers written to be added or subtracted. Space characters can be anywhere in the input. After the input ends (end-of-file is reached), the program should compute and print the result of the input summation. Possible input that has spaces and characters:1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1Possible output: 16