import sys
import re
#re.match("\(_S+\) (\S\)+")
#dfs = []
#def recurse(root, succs):
# global dfs
# for n in succs[root][1]:
# #print(last)
# recurse(n, succs)
# dfs.append(root)
def incop(r, val):
return r + val
def decop(r, val):
return r - val
def ceq(r, val):
return r == val
def clt(r, val):
return r < val
def cle(r, val):
return r <= val
def cgt(r, val):
return r > val
def cge(r, val):
return r >= val
def cne(r, val):
return r != val
def decop(r, val):
return r - val
#kd dec -37 if gm <= 9
def doit(input):
max = 0
regs = {}
lines = input.split("\n")
for l in lines:
w = l.split()
#print(w)
r = w[0]
op = w[1]
val = int(w[2])
cr = w[4]
cop = w[5]
cval = int(w[6])
if cop == "==":
pred = ceq
elif cop == "<":
pred = clt
elif cop == "<=":
pred = cle
elif cop == ">":
pred = cgt
elif cop == ">=":
pred = cge
elif cop == "!=":
pred = cne
if op == "inc":
oper = incop
else:
oper = decop
if cr not in regs: regs[cr] = 0
if r not in regs: regs[r] = 0
res=pred(regs[cr], cval)
if res:
res = oper(regs[r],val)
regs[r] = res
for r in regs:
if regs[r] > max:
max = regs[r]
return "%s" % (max)
input = sys.stdin.read()
print(doit(input))
