#include <stdio.h>

int fun (int n){

    int r;
    if(n>=20){
        printf("n = %d\n", n);
        return n;
    }

    else{
        r = n+fun(n*2);
        printf("%d\n",r);
        return r;
    }

}
int main (){
    int c =fun(5);
    printf("c =%d",c);

}