def eval_expr(s):
    tokens = []
    i = 0
    while i < len(s):
        if s[i].isspace():
            i += 1
            continue
        if s[i] in '+-*/()':
            tokens.append(s[i])
            i += 1
            continue
        if s[i].isdigit() or s[i] == '.':
            j = i + 1
            while j < len(s) and (s[j].isdigit() or s[j] == '.'):
                j += 1
            num_str = s[i:j]
            try:
                if '.' in num_str:
                    num = float(num_str)
                else:
                    num = int(num_str)
                tokens.append(num)
            except ValueError:
                raise ValueError("Invalid number") from None
            i = j
            continue
        raise ValueError("Unknown token")
    if not tokens:
        raise ValueError("Empty input")
    pos = [0]
    def peek():
        if pos[0] < len(tokens):
            return tokens[pos[0]]
        return None
    def consume():
        tok = peek()
        pos[0] += 1
        return tok
    def expr():
        result = term()
        while True:
            op = peek()
            if isinstance(op, str) and op in ('+', '-'):
                consume()
                right = term()
                if op == '+':
                    result = result + right
                else:
                    result = result - right
            else:
                break
        return result
    def term():
        result = factor()
        while True:
            op = peek()
            if isinstance(op, str) and op in ('*', '/'):
                consume()
                right = factor()
                if op == '*':
                    result = result * right
                else:
                    if right == 0:
                        raise ValueError("Division by zero")
                    result = result / right
            else:
                break
        return result
    def factor():
        sign = 1
        while True:
            op = peek()
            if isinstance(op, str) and op in ('+', '-'):
                consume()
                if op == '-':
                    sign = -sign
            else:
                break
        atom_val = atom()
        return sign * atom_val
    def atom():
        tok = peek()
        if isinstance(tok, (int, float)):
            consume()
            return tok
        if isinstance(tok, str) and tok == '(':
            consume()
            val = expr()
            if peek() != ')':
                raise ValueError("Mismatched parentheses")
            consume()
            return val
        if tok is None:
            raise ValueError("Unexpected end of input")
        raise ValueError("Unexpected token")
    result = expr()
    if peek() is not None:
        raise ValueError("Extra input after expression")
    if isinstance(result, float) and result.is_integer():
        return int(result)
    return result