Addition of 9007199254740992 and 1 gives 9007199254740992.
n = 9007199254740992 + 1; // n is equal to 9007199254740992
And, addition of 9658921879781125 and 1 gives 9658921879781124.
m = 9658921879781125 + 1; // m is equal to 9658921879781124
And, if mathematic operations in Javascript are inaccurate for large numbers, what is the way to get around this problem.