#include
int main() {
    int m, n, t;
    double fuli, dajia;
    scanf("%d", &t);
    for (int i = 0; i < t; i++) {
        scanf("%d", &n);
        scanf("%d", &m);
        temp = (m - 1) / n + 1;
        sum = temp * (n - 1);
        danjia = m / (n - 1);
        fuli = sum - m - danjia if (fuli > 0) { printf("%.6lf", fuli); }
        else {
            printf("CSFNB!")
        }
    }
}

/sandbox/1/a.c:1:9: error: expected "FILENAME" or <FILENAME>
#include
        ^
/sandbox/1/a.c:6:5: warning: implicitly declaring library function 'scanf' with type 'int (const char *restrict, ...)' [-Wimplicit-function-declaration]
    scanf("%d",&t);
    ^
/sandbox/1/a.c:6:5: note: include the header <stdio.h> or explicitly provide a declaration for 'scanf'
/sandbox/1/a.c:11:9: error: use of undeclared identifier 'temp'
        temp=(m-1)/n+1;
        ^
/sandbox/1/a.c:12:9: error: use of undeclared identifier 'sum'
        sum=temp*(n-1);
        ^
/sandbox/1/a.c:12:13: error: use of undeclared identifier 'temp'
        sum=temp*(n-1);
            ^
/sandbox/1/a.c:13:9: error: use of undeclared identifier 'danjia'; did you mean 'dajia'?
        danjia=m/(n-1);
        ^~~~~~
        dajia
/sandbox/1/a.c:5:17: note: 'dajia' declared here
    double fuli,dajia;
                ^
/sandbox/1/a.c:14:14: error: use of undeclared identifier 'sum'
        fuli=sum-m-danjia
             ^
/sandbox/1/a.c:14:20: error: use of undeclared identifier 'danjia'; did you mean 'dajia'?
        fuli=sum-m-danjia
                   ^~~~~~
                   dajia
/sandbox/1/a.c:5:17: note: 'dajia' declared here
    double fuli,dajia;
                ^
1 warning and 7 errors generated.