do you know why i got restricted function on test #5, i used math library for solve the problem, and i used fmod to get the answer

You must use long arithmetics, because size of number N is more, than the sizes of standard types. On test #5 authors use very long number.

NO! theres no need to use long arithmetics. This problem's mush more easier than waht you think.you can get AC in 0.001

I not used long arithmetics, but i have wrong answer on test 5 too.

I try do n mod 7