I'm trying to learn C by writing a simple program to output Fibonacci numbers. It isn't working.

**fibonacci.h**

```
unsigned int fibonacci_recursive(unsigned int n);

```

**fibonacci.c**

```
#include <stdio.h>
#include "fibonacci.h"

main() {
    unsigned int i;
    for (i = 0; i < 10; i++) {
        printf("%d\t%n", fibonacci_recursive(i));
    }
    getchar();
}

```

**fibonacci\_recursive.c**

```
unsigned int fib_rec(unsigned int n);

main(unsigned int n) {
     return fib_rec(n);
}

unsigned int fib_rec(unsigned int n) {
    if (n == 0) {
        return 0;
     } 
     if (n == 1) {
           return 1;
     }
     return fib_rec(n - 1) + fib_rec(n - 2);
}

```

This is the error message VS 2010 gives me when I try to build the project:

```
1>ClCompile:
1>  fibonacci_recursive.c
1>fibonacci_recursive.obj : error LNK2005: _main already defined in fibonacci.obj
1>fibonacci.obj : error LNK2019: unresolved external symbol _fibonacci_recursive referenced in function _main
1>c:\users\odp\documents\visual studio 2010\Projects\Fibonacci\Debug\Fibonacci.exe : fatal error LNK1120: 1 unresolved externals
1>
1>Build FAILED.
1>

```

What am I doing wrong here? Thanks for helping someone new to C.