PPN

#include <stdio.h>
#include <stdlib.h>

long long int ppn(void) {
    char ch = ' ';
    while (ch == ' ') {
        ch = getchar();
    }
    if (ch == '*') {
        return ppn() * ppn();
    }
    else if (ch == '/') {
        return ppn() / ppn();
    }
    else {
        long long int curr;
        if (ch == '-') {
            ch = getchar();
            curr = (-1) * (ch - '0');
        }
        else {
            curr = ch - '0';
        }
        ch = getchar();
        while (ch != ' ' && ch != EOF && ch >= '0' && ch <= '9') {
            curr = curr * 10 + ch - 48;
            ch = getchar();
        }
        return curr;
    }
}

int main(void)
{
    long long int res = ppn();
    printf("%lld", res);
    return 0;
}