#include using namespace std; int main() { string number; cin >> number; int sum_of_digits = 0; for(int i = 0; i < number.size(); i++) { sum_of_digits += (number[i] - '0'); } string result = ""; for(int i = 0; i < number.size(); i++) { int digit = (number[i] - '0'); for(int j = 0; j <= 9; j++) { if(i == 0 and j == 0) { continue; } if(j == digit) { continue; } int tmp_sum = sum_of_digits - digit + j; if(tmp_sum % 3 == 0) { string tmp_number = number; tmp_number[i] = (j + '0'); if(tmp_number > result) { result = tmp_number; } } } } cout << result << endl; return 0; }