Undeclared identifier p in for loop [closed]

What would be the solution for this even though i already declared i as an int in the for loop?

#include <stdio.h>
#include <cs50.h>

int main(void)
{
    int length;
    do
    {
        length = get_int("Length: ");
    }
    while (length < 1);

    int twice[length];
    
    for (int p = 0; p < length; p++);
    {
        twice[p] = 2 * twice[p - 1];
        printf("%i\n", twice[p]);
    }
}