#include <stdio.h>

int main() {
	int n, n1, n2, i, m;
	
	printf("Kerek egy egesz szamot: ");
	scanf("%d", &m);
	
	
	if (1 == m || 0 == m) {
		n = 1;
	} else {
		n1 = n2 = 1;
		for (i=2;i<=m;i++) {
			n = n1 + n2;
			n2 = n1;
			n1 = n;
		}
	
	
	}
	
	
	printf("F(%d) = %d\n", m, n);
	
	return 0;
}