def main():
    try:
        import pypyjit
        pypyjit.set_param('max_unroll_recursion=-1')
    except:
        pass
    try:
        import sys
        sys.setrecursionlimit(10**7)
    except:
        pass
    from math import sqrt,sin,cos,tan,ceil,radians,floor,gcd,exp,log,log10,log2,factorial,fsum
    import heapq
    from bisect import bisect_left, bisect_right
    import copy
    from collections import deque,Counter,defaultdict
    from itertools import permutations,combinations
    from decimal import Decimal,ROUND_HALF_UP
    #tmp = Decimal(mid).quantize(Decimal('0'), rounding=ROUND_HALF_UP)
    from functools import lru_cache, reduce
    #@lru_cache(maxsize=None)
    from operator import add,sub,mul,xor,and_,or_
    INF = 10**18
    mod1 = 10**9+7
    mod2 = 998244353
    
    #DecimalならPython
    
    H,W,La,Lb,Ka,Kb = map(int, input().split())

    ans = INF

    for i in range(H+1):
        l = 0
        h = W+H
        
        tmp = min(i*La,H)
        
        while h-l > 1:
            m = (l+h)//2
            
            if tmp*min(m*Lb,W) + i*Ka + m*Kb >= H*W:
                h = m
            else:
                l = m
        
        ans = min(ans, h+i)

    print(ans)
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
if __name__ == '__main__':
    main()