#include <stdio.h>
#include <math.h>

#define BIT 2

int main(void)
{
	unsigned long inputNum;

	fscanf(stdin, "%lu", &inputNum);	
	
	unsigned long mersenneNum;
	mersenneNum = pow(BIT, inputNum);
	mersenneNum--;

	unsigned long countBinaryBit = 0;
	while (mersenneNum) {
		mersenneNum /= BIT;
		countBinaryBit++;
	}

	fprintf(stdout, "%lu\n", countBinaryBit);

	return 0;
}