怎么错了？

#include <bits/stdc++.h>
using namespace std;
string thing;
long long people,flow;
int main()
{
	while(getline(cin,thing))
	{
		if(thing[0]=='+') people++;
		else if(thing[0]=='-') people--;
		else
		{
			for(int i=0;i<thing.size();i++)
			{
				if(thing[i]==':')
				{
					flow+=(thing.size()-i+1)*people;
					break;
				}
			}
		}
	}
	cout<<flow;
    return 0;
}