View Compilation Error

0_0_31169016_26728.cpp: In function 'int main(int, char**)':
0_0_31169016_26728.cpp:111:4: error: 'else' without a previous 'if'
    else if(op==2){
    ^
0_0_31169016_26728.cpp:111:12: error: 'op' was not declared in this scope
    else if(op==2){
            ^
0_0_31169016_26728.cpp:112:19: error: 'l' was not declared in this scope
     scanf("%d%d",&l,&r);
                   ^
0_0_31169016_26728.cpp:112:22: error: 'r' was not declared in this scope
     scanf("%d%d",&l,&r);
                      ^
0_0_31169016_26728.cpp:116:19: error: 'l' was not declared in this scope
     scanf("%d%d",&l,&r);
                   ^
0_0_31169016_26728.cpp:116:22: error: 'r' was not declared in this scope
     scanf("%d%d",&l,&r);
                      ^
0_0_31169016_26728.cpp: At global scope:
0_0_31169016_26728.cpp:121:5: error: expected unqualified-id before 'return'
     return 0;
     ^
0_0_31169016_26728.cpp:122:1: error: expected declaration before '}' token
 }
 ^