import sys




def main():
    n, v, c = map(int, input().split())
    dp0 = [0] * (v + 1)
    dp1 = [0] * (v + 1)
    for i in range(n):
        p0 = dp0[:]
        p1 = dp1[:]
        dp0 = [max(p0[j], p1[j]) for j in range(v + 1)]
        dp1 = [0] * (v + 1)
        a, b = map(int, input().split())
        for j in range(a, v + 1):
            dp1[j] = max(dp0[j - a] + b + c, dp1[j - a] + b)
    ans = 0
    for i in range(v + 1):
        ans = max(ans, dp0[i])
        ans = max(ans, dp1[i])
    print(ans)



if __name__ == '__main__':
    main()