Backpacking

input/code.cpp:3:10: fatal error: io.h: No such file or directory
    3 | #include "io.h"
      |          ^~~~~~
compilation terminated.

#include "stdlib.h"
#include "stdio.h"
#include "io.h"

int main(int argc, char* argv) {
    if (argc != 3 || argv[1] < 0 || argv [1] > 1000000 || argv[2] < 0 || argv [2] > 1000000) return -1;
    int tot = argv[1] + argv[2];
    return tot;
}