I dont know how to take input for the sum.
This is my code.
def main():
d={'0':0,'1':1,'2':2,'3':3,'4':4,'5':5,'6':6,'7':7,'8':8,'9':9,'A':10,'B':11,'C':12,'D':13,'E':14,'F':15}
e={0:'0',1:'1',2:'2',3:'3',4:'4',5:'5',6:'6',7:'7',8:'8',9:'9',10:'A',11:'B',12:'C',13:'D',14:'E',15:'F'}
i=0
while i!=1:
try:
i=raw_input("")
i=i.lstrip(' ')
if i.find(' ')!=-1:
g=i.find(' ')
i=list(i)
del i[g]
i=''.join(i)
if i.find(' ')!=-1:
g=i.find(' ')
i=list(i)
del i[g]
i=''.join(i)
a,b,c=i.split(' ')
b,k,c=int(b),len(a),int(c)
ans=[]
a=list(a)
a.reverse()
a=''.join(a)
dec=0
for j in range(k):
dec=dec+(d[a[j]]*(b**j))
for j in range(7):
rem=dec%c
dec=dec/c
ans.append(e[rem])
ans.reverse()
ans=''.join(ans)
ans=ans.lstrip('0')
if dec!=0:
ans="ERROR"
print "%7s"%ans
except EOFError:
break
except ValueError:
continue
main()
