draw=list(map(int,input().split()))
S=input()

b={}
for i,s in enumerate(["G","C","P"]):
    b[s]=draw[i]

point=0
for j in range(len(S)):
    if(S[j]=="G"):
        for i,s in enumerate(["P","G","C"]):
            if(b[s]!=0):
                point+=bat(s,S[j])
                b[s]-=1
                break
    if(S[j]=="C"):
        for i,s in enumerate(["G","C","P"]):
            if(b[s]!=0):
                point+=bat(s,S[j])
                b[s]-=1
                break
    if(S[j]=="P"):
        for i,s in enumerate(["C","P","G"]):
            if(b[s]!=0):
                point+=bat(s,S[j])
                b[s]-=1
                break
print(point)