s=input()
a,b=map(int,s.split())
i,j=0,0 if a*b==0 else map(int,s.replace('0','').split())
print(a*b//10 if a%100==b%100==0 and -10<i<10 and -10<j<10 else a*b if -10**8<a*b<10**8 else 'E')