---

#include <stdio.h>

int main()
{
    int a, b;
    char c;
    float sred;

    scanf("%d", &a);
    scanf(" %c", &c);
    scanf("%d", &b);

    if (c == '+')
        printf("%d\n", a + b);
    else if (c == '-')
        printf("%d\n", a - b);
    else if (c == '~')
    {
        sred = (a + b) / 2.0;
        printf("%.2f\n", sred);
    }

    return 0;
}