local mod = 1000000007
local function badd(a, b) return (a + b) % mod end
local function bsub(a, b) return (a + mod - b) % mod end
local n, m, k = io.read("*n", "*n", "*n")
local l, r = {}, {}
for i = 1, m do
  l[i], r[i] = io.read("*n", "*n")
end
local dp1, dp2 = {1}, {}
for i = 2, n do
  dp1[i] = 0
end
for ik = 1, k do
  local src = ik % 2 == 1 and dp1 or dp2
  local dst = ik % 2 == 1 and dp2 or dp1
  for i = 1, n do
    dst[i] = 0
  end
  for i = 2, n do
    src[i] = badd(src[i], src[i - 1])
  end
  for i = 1, m do
    local li, ri = l[i], r[i]
    local z = src[ri]
    if 1 < li then z = bsub(z, src[li - 1]) end
    dst[li] = badd(dst[li], z)
    if ri < n then
      dst[ri + 1] = bsub(dst[ri + 1], z)
    end
  end
  for i = 2, n do
    dst[i] = badd(dst[i], dst[i - 1])
  end
end
local tbl = k % 2 == 1 and dp2 or dp1
print(tbl[n])