#include <iostream>
#include <cstdint>
#include <cstddef>
using namespace std;
 
template <typename T>
T mod(T val, T m)
{
	T res = val % m;
	if (res < 0)
		res = res + m;
	return res;
}
 
 
int main() 
{
	const size_t SIZE = 9;
	int_fast64_t val[SIZE] = {255, 256, 257,   0, -257, -256, -255,  -1, -127863182361};
	int_fast64_t m[SIZE]   = {256, 256, 256, 256,  256,  256,  256, 256,  156};
 
	for (size_t i = 0; i < SIZE; ++i)
		cout << val[i] << " mod " << m[i] << " = " << mod(val[i], m[i]) << endl;
 
	return 0;
}

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