PROGRAMMING:Sum of three integers

Input three integers to sum and output.
###Input format:
Enter three integers on a line, separated by a space, without any additional characters.
###Output format:
Output in the order of "sum = result" in one line, where the result is output as is.
###Input example:
```in
4 5 6
```
###Output example:
```out
sum=15
```






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