from collections import *
import heapq
import bisect
import itertools


class UnionFind:
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)

        if x == y:
            return

        if self.parents[x] > self.parents[y]:
            x, y = y, x

        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def size(self, x):
        return -self.parents[self.find(x)]

    def same(self, x, y):
        return self.find(x) == self.find(y)

    def members(self, x):  # 多用すると重い
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())

    def all_group_members(self):
        group_members = defaultdict(list)
        for member in range(self.n):
            group_members[self.find(member)].append(member)
        return group_members

    def __str__(self):
        return "\n".join(f"{r}: {m}" for r, m in self.all_group_members().items())


# https://raw.githubusercontent.com/shakayami/ACL-for-python/master/segtree.py
class segtree:
    n = 1
    size = 1
    log = 2
    d = [0]
    op = None
    e = 10**15

    def __init__(self, V, OP, E):
        self.n = len(V)
        self.op = OP
        self.e = E
        self.log = (self.n - 1).bit_length()
        self.size = 1 << self.log
        self.d = [E for i in range(2 * self.size)]
        for i in range(self.n):
            self.d[self.size + i] = V[i]
        for i in range(self.size - 1, 0, -1):
            self.update(i)

    def set(self, p, x):
        assert 0 <= p and p < self.n
        p += self.size
        self.d[p] = x
        for i in range(1, self.log + 1):
            self.update(p >> i)

    def get(self, p):
        assert 0 <= p and p < self.n
        return self.d[p + self.size]

    def prod(self, l, r):
        assert 0 <= l and l <= r and r <= self.n
        sml = self.e
        smr = self.e
        l += self.size
        r += self.size
        while l < r:
            if l & 1:
                sml = self.op(sml, self.d[l])
                l += 1
            if r & 1:
                smr = self.op(self.d[r - 1], smr)
                r -= 1
            l >>= 1
            r >>= 1
        return self.op(sml, smr)

    def all_prod(self):
        return self.d[1]

    def max_right(self, l, f):
        assert 0 <= l and l <= self.n
        assert f(self.e)
        if l == self.n:
            return self.n
        l += self.size
        sm = self.e
        while 1:
            while l % 2 == 0:
                l >>= 1
            if not (f(self.op(sm, self.d[l]))):
                while l < self.size:
                    l = 2 * l
                    if f(self.op(sm, self.d[l])):
                        sm = self.op(sm, self.d[l])
                        l += 1
                return l - self.size
            sm = self.op(sm, self.d[l])
            l += 1
            if (l & -l) == l:
                break
        return self.n

    def min_left(self, r, f):
        assert 0 <= r and r <= self.n
        assert f(self.e)
        if r == 0:
            return 0
        r += self.size
        sm = self.e
        while 1:
            r -= 1
            while r > 1 and (r % 2):
                r >>= 1
            if not (f(self.op(self.d[r], sm))):
                while r < self.size:
                    r = 2 * r + 1
                    if f(self.op(self.d[r], sm)):
                        sm = self.op(self.d[r], sm)
                        r -= 1
                return r + 1 - self.size
            sm = self.op(self.d[r], sm)
            if (r & -r) == r:
                break
        return 0

    def update(self, k):
        self.d[k] = self.op(self.d[2 * k], self.d[2 * k + 1])

    def __str__(self):
        return str([self.get(i) for i in range(self.n)])

    def get_list(self):
        return [self.get(i) for i in range(self.n)]  # オリジナルで追加


# RMQのとき
# def op(x, y):
#    return x if x < y else y
# seg = segtree([10**9] * N, op, 10**9)  # Vの要素とEの値は同じにする #10**9 -> INF
# seg.prod(l, r) # op(a[l],...a[r-1])を返す


# リストを渡すと座標圧縮して返してくれる
def compress(arr):
    (*XS,) = set(arr)
    XS.sort()
    return {cmp_e: cmp_i for cmp_i, cmp_e in enumerate(XS)}


def ctov(c):
    return ord(c) - ord("a")


def CTOV(c):
    return ord(c) - ord("A")


dxdy1 = ((0, 1), (0, -1), (1, 0), (-1, 0))
dxdy2 = ((0, 1), (0, -1), (1, 0), (-1, 0), (1, 1), (-1, -1), (1, -1), (-1, 1))
dxdy3 = ((0, 1), (1, 0))
INF = float("inf")
MOD = 998244353
mod = 998244353

W, Z, B = map(float, input().split())
print(int((W + Z) * (1.0 + B)))