#include <cstdio>
int main() {
    int F = 0;
    int k = 10000;
    int x = 0;
    int sign = 1;
    char c = getchar();
    while ((c < '0' || c > '9') && c != '-') c = getchar();
    if (c == '-') {
        c = getchar();
        sign = -1;
    }
    while ((c >= '0' && c <= '9') || c == '.') {
        if (c != '.')
            x = x * 10 + c - '0';
        c = getchar();
    }
    x *= sign;
    x -= 320000;
    F = x * 10;
    int C = 0;
    C = (F * 5) / 9;
    int mu = C % 10;
    if (mu >= 5) {
        C = C + 10;
    }
    else if(mu<=-5){
    	C = C - 10;
	}
    C = C / 10;
    sign = 1;
    if (C < 0) {
        sign = -1;
        C = -C;
    }
    if (sign < 0)
        putchar('-');
    printf("%d.%04d\n", C / k, C % k);
}