include iostream using namespace std int main string from to getline c

#include <iostream>

using namespace std;

int main()
{
	string from,to;
	getline(cin,from);
	getline(cin,to);
	string line;
	while(getline(cin,line))
	{
		if (from!=to)
		{
			int lastpos = 0;
			while ((lastpos=line.find(from, lastpos))!=string::npos)
			{
				line.replace(lastpos,from.length(),to);
				lastpos+=from.length();
			}
		}
		cout << line << endl;
	}
}