Binary Sum

#include<bits/stdc++.h>
using namespace std;
string toBinary(int n)
{
    string s;
    while(n)
    {
        s.push_back((n%2)+'0');
        n/=2;
    }
    reverse(s.begin(),s.end());
    return s;
}
string sum(string a, string b)
{
    reverse(a.begin(),a.end());
    reverse(b.begin(),b.end());
    while(a.size()!=b.size())
    {
        if(a.size()<b.size())
            a.push_back('0');
        else
            b.push_back(48);
    }

    int carry=0,temp;
    string ans="";
    for(int i=0; i<a.size(); i++)
    {
        temp=(a[i]-48)+(b[i]-48);
        temp+=carry;
        carry=0;
        ans.push_back((temp%2)+48);
        carry=((temp/2)%2);
    }
    //cout<<"carry = "<<carry<<endl;
    while(carry)
    {
        ans.push_back((carry%2)+48);
        carry/=2;
    }
    reverse(ans.begin(),ans.end());
    return ans;
}
int main()
{
    string a,b;
    cin>>a>>b;
    cout<<sum(a,b)<<endl;
}