#include <stdio.h>

int main () {
  char h[200003] = "";
  char s[200003] = "";
  
  int res = 0;
  
  int idx1 = 0;
  int idx2 = 0;
  
  res = scanf("%s", h);
  res = scanf("%s", s);
  
  while (h[idx1] != '\0') {
    idx1++;
  }
  while (s[idx2] != '\0') {
    idx2++;
  }
  
  if (((int)(h[idx1-1]))%2 == ((int)(s[idx2-1]))%2) {
    printf("Possible\n");
  } else {
    printf("Impossible\n");
  }
  
  return 0;
}