#
# See ../README.md
#

#
# Run as: bc ch-1.bc < input-file
# End first line with a 0.
#

while (1) {
    a = read ()
    if (a == 0) {break}
    a [i] = a
    i = i + 1
}

for (j = 0; j < i; j ++) {
    sum += a [j] * read ()
}

sum