#include <stdio.h>
#include <string.h>

int main() {
  char n[200];
  scanf("%s", n);
  int count = 0;
  int len = strlen(n);
  for (int i = 0; i < len; i++) {
    if (n[i] == '1') {
      count += 1;
    }
  }
  if (count % 2 == 0) {
    printf("%s0\n", n);
  } else {
    printf("%s1\n", n);
  }
  return 0;
}


Input

Each test case consists of one line containing the message S, which has at least 1 and at most 100 bits.


char n[???];

What is the correct array size here?