def calcmin(seq,x,y):
    def add(l,n):
        l[0]+=n[0]
        l[1]+=n[1]
    ones, zeros = [0,0],[0,0]
    oz =[0,0]
    zo = [0,0]
    for c in seq:
        if c == '0':
            add(oz,ones)
            add(zeros,[1,1])
        elif c == '1':
            add(zo,zeros)
            add(ones,[1,1])
        elif c == '!':
            # ! is 0
            oz[0] += ones[0]
            zeros[0]+=1
            # ! is 1
            zo[1] += zeros[1]
            ones[1]+=1

    return min(zo[0]*x+oz[0]*y,zo[1]*x+oz[1]*y)