#include <stdio.h>
#include <cstdint>
#include <iostream>
uint64_t foo(uint8_t* A, uint8_t* B, uint8_t* C)
{
uint64_t aux = 0;
aux = A[0];
aux <<= 8;
aux |= A[1];
aux <<= 8;
aux |= B[0];
aux <<= 8;
aux |= B[1];
aux <<= 8;
aux |= C[0];
aux <<= 8;
aux |= C[1];
return aux;
}
int main()
{
uint8_t a[] = { 0x12, 0x34 };
uint8_t b[] = { 0x56, 0x78 };
uint8_t c[] = { 0x9a, 0xbc };
uint64_t result = foo(a, b, c);
std::cout << std::hex << result;
return 0;
}