#include<bits/stdc++.h>
using namespace std;
char c;
char x;
int f=0;
int num=0,xn=0,a=0;
int main()
{
	cin>>x;
	while(x!='=')
	{
		if(isalpha(x))
		{
			xn+=f?a:-a;
			a=0;
			c=x;
		}
		else if(x=='+')
		{
			num-=f?-a:a;
			a=0;
			f=0;
		}
		else if(x=='-')
		{
			num-=f?-a:a;
			a=0;
			f=1;
		}
		else if(isdigit(x))    a=a*10+(x-'0');
		cin>>x;
	}
	while(cin>>x)
	{
		if(isalpha(x))
		{
			xn-=f?a:-a;
			a=0;
			c=x;
		}
		else if(x=='+')
		{
			num+=f?-a:a;
			a=0;
			f=0;
		}
		else if(x=='-')
		{
			num+=f?-a:a;
			a=0;
			f=1;
		}
		else if(isdigit(x))    a=a*10+(x-'0');
	}
	if(num==xn)    cout<<c<<"=0.000";
	else    printf("%c=%.3f",c,num*1.0/xn);
	return 0;
}

https://www.luogu.com.cn/record/200601153