输出数值不对，什么问题？

#include<iostream>
#include<stack>
#include<string>
using namespace std;
stack<int> q;
string s;
int main()
{
	getline(cin,s);
	int l=s.size()-1;
	int number=0,sum=0;
	bool cheng=false;
	for(int i=0;i<=l;i++)
	{
		if(s[i]>='0'&&s[i]<='9')
			number=(number*10+int(s[i]-48))%10000;
		else
		{
			if(cheng==false)//判断这个数前有没有×号
				q.push(number);
			else//有则把栈顶与此数相乘
			{
				number=(number%10000*q.top()%10000)%10000;
				q.pop();
				q.push(number);
				//cout<<q.top()<<endl;
				cheng=false;
			}
			number=0;
			if(s[i]=='*')
			{
				cheng=true;
			}
		}
	}
	while(!q.empty())
	{
		sum+=q.top();
		sum%=10000;
		//cout<<sum<<" "<<q.top()<<endl;
		q.pop();
	}
	cout<<sum;
	return 0;
}