#include <stdio.h>
char F[2][201];int main(){FILE*fi;fi=fopen("nunta.in","r");short n;fscanf(fi,"%hd", &n);fclose(fi);fi=fopen("nunta.out","w");if(n == 1){fprintf(fi,"1");return 0;}F[0][1] = 1;F[1][1] = 2;unsigned char i, t;short j;for(j = 3; j <= n; j++){t = 0;for(i = 1; i <= 199 || t; i++, t/=10)F[1 - j % 2][i] = (t += F[0][i] + F[1][i]) % 10;}i = 199;while(F[1 - n % 2][i] == 0) i--;while(i > 0)fputc(F[1 - n % 2][i--] + '0', fi);return 0;}