#include <stdio.h>
int a(int n){
	int a,b,i;
	a=0;
	for(i=0;i<n;i++){
		a=3*b+4;
		b=a;
	} 
	return a;
}
int main(void) {
	int n;
	n=2;
 
	return 0;
}
 
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