ans=10000
n,x,y=map(int,input().split())
def dfs(num) :
    if num-x<=0 and num-y<=0 :
        global ans
        ans=min(ans,num)
        return 
    if(num-x>0) : dfs(num-x)
    if(num-y>0) : dfs(num-y)
    
dfs(n)
print(ans)
\OvO/