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

int main() {
  int v = 0;
  int db[10] = {0};
  char n[1001];

  while (scanf("%s", n) != EOF) {
    memset(db, 0, sizeof db);
    v = 0;
    int len = strlen(n);
    for (int i = 0; i < len; i++) {
      db[n[i]-48] += 1;
      if (db[n[i]-48] > v){
        v = db[n[i]-48];
      }
    }
    for (int i = 9; i >= 0; i--) {
      if (db[i] == v){
        printf("%d\n", i);
        break;
      }
    }
  }
  return 0;
}


This answer worked
thanks