#include <stdio.h>

int main()

{

int user[30] = {0,};

int n = 0;

int count = 0;

for (int i = 0; i < 30; i++) {

user[i] = i + 1;

}

while ((n < 0 || n>31) || count!=28)

{

scanf_s("%d", &n);

for (int i = 0; i < 30; i++) {

if (user[i] == n)

user[i] = 0;

else

continue;

}

count++;

}

for (int i = 0; i < 30; i++)

{

if (user[i] > 0)

printf("%d\n", user[i]);

else

continue;

}

 

return 0; 

}