#include int main(void){ int i, j; int K; int S[6] = {2,3,5,7,11,13}; int G[6] = {4,6,8,9,10,12}; int n = 0; scanf("%d", &K); for(i = 0; i < 6; i++){ for(j = 0; j < 6; j++){ if(S[i] * G[j] == K) n++; } } printf("%lf\n", (double)n / 36); return 0; }