#include <stdio.h>
#include <stdlib.h>

extern "C"{
  int inc_one(int x);
}

void setup() {
  Serial1.begin(9600);
}

int main(){
  int x,y,increased;
  printf("Enter the number x: ");
  scanf("%d",&x);
  printf("%d\n",x);
  increased = inc_one(x);
  printf("Increased number = %d\n",increased);
  return 0;
}