MOD = 10**9 + 7

def main():
    import sys
    input = sys.stdin.read
    data = input().split()
    idx = 0
    N = int(data[idx]); idx += 1
    M = int(data[idx]); idx += 1
    K = int(data[idx]); idx += 1

    elevators = []
    for _ in range(M):
        L = int(data[idx]); idx += 1
        R = int(data[idx]); idx += 1
        elevators.append((L, R))
    
    # DP state: dp_prev[x] is the number of ways to be at floor x after k moves
    dp_prev = [0] * (N + 2)  # 1-based indexing, ignoring 0, N+1 is buffer
    dp_prev[1] = 1

    for _ in range(K):
        # Compute prefix sum for dp_prev
        prefix = [0] * (N + 2)
        for x in range(1, N + 1):
            prefix[x] = (prefix[x-1] + dp_prev[x]) % MOD
        
        # Initialize difference array
        diff = [0] * (N + 2)
        for L, R in elevators:
            # Calculate sum S of dp_prev[x] for x in [L, R]
            S = (prefix[R] - prefix[L-1]) % MOD
            # Apply range [L, R] addition of S
            diff[L] = (diff[L] + S) % MOD
            if R + 1 <= N:
                diff[R+1] = (diff[R+1] - S) % MOD
        
        # Compute dp_next from the difference array
        current = 0
        dp_next = [0] * (N + 2)
        for y in range(1, N + 1):
            current = (current + diff[y]) % MOD
            dp_next[y] = current % MOD
        
        # Update for next iteration
        dp_prev = dp_next
    
    print(dp_prev[N] % MOD)

if __name__ == "__main__":
    main()