x = int(input())
p = 1
for i in range(x):
row = input()
row=row+'b'
strona=1
liczba=0
wolne=0
zmienne=0
#print(row)
j=0
while j<len(row) - 1:
liczba=0
while row[j] in ("012345689"):
liczba=liczba*10+int(row[j])
j+=1
#print(j, " ", liczba)
if row[j] == 'x':
if liczba==0:
liczba=1
zmienne+=liczba*p*strona
else:
zmienne += liczba * p * strona
else:
wolne+=liczba*p*strona
p=1
#print('w'," ",wolne," ",'z',zmienne," ",p)
if row[j] == '=':
strona=-1
elif row[j] == 'b':
break
elif row[j] == '+':
p = 1
elif row[j] == '-':
p = -1
j+=1
#print('w'," ",wolne," ",'z'," ",zmienne)
if zmienne==0 or wolne==0:
print("NO")
else:
print(-(wolne/zmienne))
{"html5":"htmlmixed","css":"css","javascript":"javascript","php":"php","python":"python","ruby":"ruby","lua":"text\/x-lua","bash":"text\/x-sh","go":"go","c":"text\/x-csrc","cpp":"text\/x-c++src","diff":"diff","latex":"stex","sql":"sql","xml":"xml","apl":"apl","asterisk":"asterisk","c_loadrunner":"text\/x-csrc","c_mac":"text\/x-csrc","coffeescript":"text\/x-coffeescript","csharp":"text\/x-csharp","d":"d","ecmascript":"javascript","erlang":"erlang","groovy":"text\/x-groovy","haskell":"text\/x-haskell","haxe":"text\/x-haxe","html4strict":"htmlmixed","java":"text\/x-java","java5":"text\/x-java","jquery":"javascript","mirc":"mirc","mysql":"sql","ocaml":"text\/x-ocaml","pascal":"text\/x-pascal","perl":"perl","perl6":"perl","plsql":"sql","properties":"text\/x-properties","q":"text\/x-q","scala":"scala","scheme":"text\/x-scheme","tcl":"text\/x-tcl","vb":"text\/x-vb","verilog":"text\/x-verilog","yaml":"text\/x-yaml","z80":"text\/x-z80"}