View Compilation Error

0_0_39639193_5756.cpp:5:1: error: expected initializer before 'int'
    5 | int solve(int);
      | ^~~
0_0_39639193_5756.cpp: In function 'int main()':
0_0_39639193_5756.cpp:7:9: error: 'fb' was not declared in this scope
    7 |         fb[1]=1;fb[2]=2
      |         ^~
0_0_39639193_5756.cpp: In function 'int solve(int)':
0_0_39639193_5756.cpp:14:12: error: 'fb' was not declared in this scope
   14 |         if(fb[n]!=0) return fb[n];
      |            ^~