========================================== solve.cpp
#include <cstdint>
#include <iostream>

extern "C" uint64_t ArgSum(uint64_t a, uint64_t b, uint64_t c, uint64_t d);

int main() {
    unsigned long long a, b, c, d;
    std::cin >> a >> b >> c >> d;
    std::cout << ArgSum(a, b, c, d);
}

========================================== solve.S
.intel_syntax noprefix
.section .note.GNU-stack

.section .text

.global ArgSum
ArgSum:
    // TODO: your code here.
    ret