View Compilation Error

0_0_15216679_17707.cpp:25:9: error: 'LL' was not declared in this scope
 int gcd(LL x,LL y)
         ^
0_0_15216679_17707.cpp:25:14: error: 'LL' was not declared in this scope
 int gcd(LL x,LL y)
              ^
0_0_15216679_17707.cpp:25:18: error: expression list treated as compound expression in initializer [-fpermissive]
 int gcd(LL x,LL y)
                  ^
0_0_15216679_17707.cpp:26:1: error: expected ',' or ';' before '{' token
 {
 ^
0_0_15216679_17707.cpp: In function 'int main()':
0_0_15216679_17707.cpp:33:5: error: 'LL' was not declared in this scope
     LL N,M;
     ^
0_0_15216679_17707.cpp:37:27: error: 'N' was not declared in this scope
         scanf("%lld%lld",&N,&M);
                           ^
0_0_15216679_17707.cpp:37:30: error: 'M' was not declared in this scope
         scanf("%lld%lld",&N,&M);
                              ^
0_0_15216679_17707.cpp:47:30: error: 'gcd' cannot be used as a function
             int k = gcd(M%N,N);
                              ^