这个为啥输入3层汉诺塔，输出8啊QAQ

#include<stdio.h>
int count = 0;
int a = 0;
int b = 0;
int c = 0;
int co(int x)
{
    a = x;
    if (a > 2)
    {
        b = a - 1;
        count += 2;
        c += 1;
        a = b - 1;
        count += 2;
        c += 1;
        for (;a>2;)
            co(b - 1);
        return count;
    }
    else if (a = 2)
        return 3;
    else if (a = 1)
        return 1;
}
int main()
{
    int n = 0;
    scanf_s("%d", &n);
    co(n);
    printf("%d", co(n));
    return 0;
}