#include <stdio.h>

int main() {
    int operationType;
    double num1,num2;
    
    scanf("%d", &operationType);
    scanf("%lf %lf", &num1,&num2);
    
    if (operationType == 1){
        printf("%.2lf", num1 + num2);
    }
    else if (operationType == 2) {
        printf("%.2lf", num1 - num2);
        
    }
    else if (operationType == 3);
{
    printf("%.2lf", num1*num2);
}

    else if (operationType == 4) {
        
        if(num2 == 0) {
            
            printf("Division by zero");
        }
        else {
            
            printf("%.2lf", num1 / num2);
        }
    }
    else {
        printf("Invalid input");
    }
    
    return 0;
}