int main(){
    int n;
    cin>>n;
    int a[3],b[3];
    for(int i=0;i<3;i++){
        cin>>a[i]>>b[i];
    }
    int num1=0,num2=0,num3=0,sum1=0,sum2=0,sum3=0;
    do{
        num1+=a[0];
        sum1+=b[0];
    }while(num1>=n);
    do{
        num2+=a[1];
        sum2+=b[1];
    }while(num2>=n);
    do{
        num3+=a[2];
        sum3+=b[2];
    }while(num3>=n);
    int min=sum1;
    if(min>sum2) min=sum2;
    if(min>sum3) min=sum3;
    cout<<min;
}