Calculator Program

Interview

Time limit1sMemory limit128 MB

Summary

Read alternating numbers and operators, evaluate left to right ignoring precedence, and print the value when = appears.

Level: Easy3 of 10
Topics: Implementation, Simulation, Math, String
Solved: No attempts yet

Problem

Write a calculator program that can perform addition, subtraction, multiplication, and division.

Input

The input consists of several lines. Each line contains a number or one of the operators (+, -, *, /, =), given alternately. The first line is a number.

Operator precedence is ignored; the calculation is performed from left to right in the order the input is given. When = is given, print the result computed so far.

Each given number is a positive integer at most $10^8$ . An intermediate result may be $0$ or negative, but it never leaves the range $-10^8 \sim 10^8$ .

In division, the fractional part is discarded. For example, 100 / 3 * 3 = 99.

Division in which the dividend (the number being divided) is negative is never given as input.

Output

Print the result of the calculation on the first line.

Examples3

Example 1
Input
```
1
+
1
=
```
Expected output
```
2
```
Example 2
Input
```
10
-
21
*
5
=
```
Expected output
```
-55
```
Example 3
Input
```
100
/
3
*
3
=
```
Expected output
```
99
```