1006. 捡石头

3 5 7

5

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cmath>
 4 using namespace std;
 5 int r,x,p;
 6 int main()
 7 {
 8     cin>>r>>x>>p;
 9     printf("%d",20-r-x-p);
10     return 0;
11 }