#include <bits/stdc++.h>
using namespace std;
int MXN=1e7,w,xn,n;
char wzs;
struct bds{
	string s;
	int xn,n;
};
bool zm(char c){return (c>='a'&&c<='z');}
int read(string n){
	int ans=0;
	char ch=n[1],c;
	c=n[0];
	if(c>='0'&&c<='9') ans+=c-'0';
	for(w=1;w<n.size();w++){
		if(ch=='+'||ch=='-'||ch=='='||zm(ch)) break;
		ans=ans*10+ch-'0';
		ch=n[w+1];
	}
	if(c=='-') return -ans;
	return ans;
}
int cd(string n){
	int i;
	for(i=1;i<n.size();i++) if(n[i]=='+'||n[i]=='-'||n[i]=='='||zm(n[i])) break;
	return i;
}
bds a[3];
char ch;
int main(){
while(ch!='='){
	ch=getchar();
	a[1].s+=ch;
}
a[1].s.erase(a[1].s.size()-1,1);
while(ch!='\n'){
	ch=getchar();
	a[2].s+=ch;
}
a[2].s.erase(a[2].s.size()-1,1);
for(int i=1;i<3;i++){
	while(a[i].s.size()){
		if(zm(a[i].s[cd(a[i].s)])){
			wzs=a[i].s[cd(a[i].s)];
			a[i].xn+=read(a[i].s);
		}
		else a[i].n+=read(a[i].s);
		a[i].s.erase(0,cd(a[i].s));
	}
}
printf("%c=%.3f",wzs,-((a[1].n-a[2].n)*1.0/(a[1].xn-a[2].xn)));
return 0;
}

数据到编译器里是对的，但是提交就是WA