What will be the output of the following C program?

#include <stdio.h>
int main()
{
int f1(int,int);
int x = 9,n = 3;
printf("%d", f1(x, n));
}
int f1(int x, int n)
{
int y = 1,i = 1;
for(i = 1;i <= n; i++)
y = y * x;
return(y);
}

x = 9, n = 3;
int f1(int x, int n)
{
int y = 1,i = 1;
for(i = 1;i <= n; i++)
y = y * x;
return(y);
}
i = 1,
y = 1, x = 9, n = 3,
y = 1*9 = 9
i = 2,
y = 9, x = 9, n = 3,
y = 9*9 = 81
i = 3,
y = 81, x = 9, n = 3,
y = 81*9 = 729
return (y) i.e. 729

@air1 I first declare the function inside the main function. Then after some code. I define that function inside the main function. I got thiserror: "error: a function-definition is not allowed here before '{' token {"