OJ-Problems-Source/HDOJ/2013_autoAC.cpp
2016-08-19 16:52:35 +08:00

10 lines
174 B
C++

#include <math.h>
#include <stdio.h>
int main(void)
{
int n;
while (scanf("%d", &n) != EOF)
printf("%.0f\n", 3 * pow(2, n - 1) - 2);
return 0;
}