#include <iostream>

#define LIMIT 1000002

using namespace std;

char *chars;
int charsLength;
char *builder;
int builderLength;

bool endsWith(char c1, char c2) {
    if(charsLength <= 0) {
        return c1 == '0' && c2 == '0';
    }
    if(charsLength >= 2) {
        return chars[charsLength-2] == c1 && chars[charsLength-1] == c2;
    }
    return chars[0] == c2 && c1 == '0';
}


int main(int argc, char **argv) {
    bool shouldContinue;

    builder = new char[LIMIT];
    chars = new char[LIMIT];

    while(cin.getline(chars, LIMIT)) {
        for(int i=0; i < LIMIT; i++) {
            if(chars[i] == 0) {
                charsLength = i;
                break;
            }
        }

        builderLength = 0;
        shouldContinue = true;

        while(shouldContinue) {
            shouldContinue = false;
            if(endsWith('0', '1')) {
                builder[builderLength++] = '0';
                builder[builderLength++] = '1';
                shouldContinue = true;
            } else if(endsWith('1', '1')) {
                builder[builderLength++] = '0';
                builder[builderLength++] = '0';
            }
            else if(endsWith('1', '0')) {
               builder[builderLength++] = '1';
               builder[builderLength++] = '1';
            }
            else if(endsWith('0', '0')) {
               builder[builderLength++] = '1';
               builder[builderLength++] = '0';
            }
            charsLength -= 2;
        }

        if(charsLength < 0) {
            charsLength = 0;
        }

        for(int i=0; i<builderLength; i++) {
            chars[charsLength+i] = builder[builderLength-i-1];
        }
        charsLength += builderLength;

        bool found = false;
        for(int i=0; i<charsLength; i++) {
            if(chars[i] == '1') {
                found = true;
                cout << '1';
            } else if(found) {
                cout << '0';
            }
        }

        if(found == false) {
            cout << '0';
        }
        cout << endl;
    }
    return 0;
}