int N,M;//注意题目说x为正整数,0不算int Extend_euc(int a,int b,int&x,int&y) {    if(b==0) {x=1,y=0;return a;}    int d=Extend_euc(b,a%b,x,y);    int tmp=x; x=y; y=tmp-(a/b)*y;    return d;}void modeq(int a,int b,int n) {    int e,i,d,x,y,tmp;    d=Extend_euc(a,n,x,y);    if(b%d>0) puts("Not Exist");    else {        e=((x*(b/d))%n+n)%n;        printf("%d\n",e);    }}void get_data() {    int i,j,k;    scanf("%d%d",&N,&M);}void solve() {    int i,j,k;    if(M==1) puts("1");    else modeq(N,1,M);}